Today we’re looking at words for magic, spells, charms, prayers and related things in Celtic languages.

| Proto-Celtic | *brixtā = spell, magical formula, incantation | 
| Celtiberian | *bruxtia | 
| Gaulish | brixtia | 
| Old Irish (Goídelc) | bricht = charm, spell, incantation | 
| Middle Irish (Gaoidhealg) | bricht = incanation, charm, magic spell | 
| Irish (Gaeilge) | briocht = charm, spell, amulet briocht sí = fairy charm
 briocht a chanadh = to chant a spell
 briocht draíochta = magic spell
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| Proto-Brythonic | *briθ [ˈbriːθ] = charm, incantation | 
| Middle Welsh (Kymraec) | lleturith, lledrith, ledryth = magic, spell, charm, enchantment llethrithawc, lledrithyawc, lleturithawc = magic, magical, enchanted
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| Welsh (Cymraeg) | lled(f)rith = magic, spell, charm, enchantment; apparition, spectre, phantom; illusion, delusion, fantasy, imagination lledrithaid = pretence, dissembling, deception
 lledrithiaf, lledrithio = to counterfeit, fake, pretend, simulate
 lledrithiog = magic, magical, enchanted
 | 
| Old Breton | brith = charm, incantation (?) | 
| Breton (Brezhoneg) | bre = incantation, magic | 
Etymology: from the Proto-Indo-European *bʰerHǵ- (enlighten). Words that probably come from the same Proto-Celtic root, via the Celtiberian *bruxtia, include bruja (witch, crone, hag, owl) in Spanish, bruxa (witch, hex) in Galician, bruxa (witch) in Portuguese, and bruixa (witch) in Catalan [source].
| Old Irish (Goídelc) | druídecht, draídecht = magic, wizardry, secret lore and arts of the druids | 
| Middle Irish (Gaoidhealg) | druídecht, draídecht, dráoidheachd = secret lore and arts of the druids, occult science, wizardry | 
| Irish (Gaeilge) | dríocht [ˈd̪ˠɾˠihaxt̪ˠə] = druidic art, druidism, witchcraft, magic, charm, enchantment draíochtach = magical, bewitching, entrancing
 draíochtúil = magic, magical
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| Scottish Gaelic (Gàidhlig) | draoidheachd [drɯjəxg] = magic, socery, druidism eun-draoidheachd = augury
 slat-draoidheachd = magic wand/td>
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| Manx (Gaelg) | druaight = charm, druid druaightagh = charmer, charming, druid, magician, occult
 druaightys = charming, druid, druidism, magic
 fo druaight = charmed
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| Welsh (Cymraeg) | derwyddiaeth [dɛrˈwəðjaɨ̯θ/dɛrˈwəðjai̯θ] = druidism, the druid cult | 
| Cornish (Kerneweg) | drewydhieth = druidism | 
| Breton (Brezhoneg) | drouizelezh / drouiziezh = druidism | 
Etymology: these words come from the same roots as words for druid.
| Old Irish (Goídelc) | ortha = prayer, incantation, spell, charm oráit = prayer
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| Middle Irish (Gaoidhealg) | ortha, órtha = prayer, incantation, spell, charm orthanach = of prayers, wont to pray
 oróit, oráit, oráid, oraoid = prayer, speech, oration
 anoráit, anóráid = curse
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| Irish (Gaeilge) | ortha = incantation, spell, charm, prayer im ortha = unsalted butter used in charm-cure
 óráid = oration, speech, address
 óráideach = oratorical, declamatory.
 óráidí = orator, speech-maker
 óráidíocht = oratory, speech-making
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| Scottish Gaelic (Gàidhlig) | ortha [ɔr̪ˠə] = incantation, (magical) prayer, amulet ortha-bhàis = death incantation
 ortha-ghràidh = love amulet / charm
 òraid [ɔːrɪdʲ] = address, speech, lecture, talk
 òraidiche [ɔːrɪdʲɪçə] = lecturer, orator, speechmaker
 òraidearachd = oratory
 talla-òraid = lecture hall / theatre
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| Manx (Gaelg) | oraid = address, oration, speech oraatagh = orator, speaker, oratorial
 oraataght = oration
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| Proto-Brythonic | *arọd = prayer, oration | 
| Old Welsh (Kembraec) | araut = speech, language, eloquence, address, oration | 
| Middle Welsh (Kymraec) | araỽd, arawt, araỽt, arawd = speech, language, eloquence, address, oration | 
| Welsh (Cymraeg) | arawd = speech, language, eloquence, address, oration, utterance, report, eulogy, prayer arawduriaeth = oratory, rhetoric
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| Middle Cornish (Cernewec) | areth = speech, oration | 
| Cornish (Kerneweg) | areth = lecture, oration, speech arethek = rhetorical
 arethor, arethores = lecturer, orator, speaker
 arethva = platform
 arethya = to lecture
 | 
Etymology: from Latin ōrātiō (speech, discourse, language, oration), from ōrō (to speak as an orator, plead, pray) from Latin ōs, ōris (mouth), or from Proto-Indo-European *h₂er- (to pronounce a ritual) [source]. 
The words for prayer and oration come from this Latin root, and the words for charm and incantation may do as well [source]. The Brythonic words come via Vulgar Latin *arātiō [source].
Words from the same roots include oration in English, oración (oration, sentence, clause, prayer) in Spanish, and oratorio (oratory, oratorio, oratorical, solemn) in Italian.
| Old Irish (Goídelc) | sén = blessing, charm, incantation, omen, prosperity, sign, snare sénaid = to bless, charm (with spell), deny, reject, repudiate, sign
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| Middle Irish (Gaoidhealg) | sén, seon, seún, sena, séna = sign, omen, augury, portent, incantation, charm, blessing, good luck, prosperity, happiness sénaid, seanaidh = to mark with a sign, bless, put a spell on, put a charm on
 | 
| Irish (Gaeilge) | séan [ʃeːnˠ] = sign, omen, good luck, prosperity; to mark with a sign, to bless séanaire = diviner, augur
 séanaireacht = divination, augury
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| Scottish Gaelic (Gàidhlig) | seun [ʃiən] = charm, magic invocation, protective spell seunach [ʃiənəx] = charming, enchanting, charm-like
 seunadair [ʃiənədɪrʲ] = enchanter
 seunadaireachd [ʃiənədɪrʲəxg] = conjuring, enchanting
 seunail [ʃiənal] = charmed, magical, happy, prosperous
 seunmhorachd [ʃiənvərəxg] = magical power(s)
 seunta [ʃiən̪ˠdə] = charmed, enchanted
 seuntachan [ʃiəndəxan] = charm, enchantment
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| Manx (Gaelg) | sheean = charm, fortune | 
| Proto-Brythonic | *suɨɣn = spell, incantation (?) | 
| Middle Welsh (Kymraec) | swyn, suen,  = spell, incantation, sorcery, witchcraft, magic, remedy, charm swyno, suyno = to charm, fascinate, allure, cast a spell (on), bewitch
 swynedig, sỽynedic, swynedic = charmed, fascinated, charming, bewitched, blessed, happy
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| Welsh (Cymraeg) | swyn [suːɨ̯n / sʊi̯n] = spell, incantation, sorcery, witchcraft, magic, remedy, charm swyn(i)o = to charm, fascinate, allure, cast a spell (on), bewitch, divine, bless, protect
 swynaidd = charming, enchanting
 swynedig = charmed, fascinated, charming, bewitched, blessed, happy
 swynwr, swynydd = sorcerer, magician, bewitcher, soothsayer
 swynyddiaeth = sorcery, witchcraft, magic
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| Middle Cornish (Cernewec) | sona, sone = to bless, hallow, sanctify, consecrate, charm zona = to charm, hallow
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| Cornish (Kerneweg) | sona = to bless, charm sonell = charm
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| Breton (Brezhoneg) | saouzan = disorientation, bewilderment, stupor, hypnosis saouzanan, saouzanañ = to disorientate, hypnotise, go astray, misplace
 saouzanidigezh = hypnotism
 saouzanus = hypnotic
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Etymology: from Latin signum (sign, mark, signal, miracle), from Proto-Italic *seknom (sign, statue), from Proto-Indo-European *sek- (to cut) or  *sekʷ- (to follow). [source]. 
Words from the same roots include sign and signal in English, seña (sign, indication, gesture) and sino (destiny, fate, lot) in Spanish, and Segen (blessing) in German [source].
| Proto-Celtic | *soitos. *soyto- = magic | 
| Proto-Brythonic | *hʉd = magic, charm hʉdol = charming, illusory
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| Middle Welsh (Kymraec) | hut, hud = magic, wizardry, sorcery, witchcraft hûdadwy, hydadwy = persuasive, enticing, seducible
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| Welsh (Cymraeg) | hud [hɨːd/hiːd] = magic, wizardry, sorcery, witchcraft, spell, enchantment, charm, fascination, allurement, persuasion hudadwy = persuasive, enticing, seducible
 hudaf, hudo = to fashion or produce by magic, conjure, cast a spell upon, enchant, charm, entice, allure, persuade, seduce, beguile
 hudaidd = alluring, charming, seductive
 hudol = charming, enchanting, enticing, alluring, illusory, deceptive, deceitful
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| Old Cornish | hudol = charming, illusory | 
| Middle Cornish (Cernewec) | huder = a deceiver, hypocritic, juggler, sorcerer hudol = sorcerer
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| Cornish (Kerneweg) | hus = charm, enchantment, illusion, magic, sorcery, spell husa = to charm, create an illusion, enchant
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| Middle Breton (Brezonec) | hud = magic hudek, hudel = magic, magical
 hudiñ = to charm, enchant, bewitch, delight
 hudour = magician, wizard
 hudouriezh = magic
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| Breton (Brezhoneg) | hud = magic hudek = magic, magical
 hudour = magician, wizard
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Etymology: from the Proto-Indo-Etymology *sh₂oy-tó-s (magic), from *sh₂ey (to bind, fetter) [source]. Words from the same PIE roots include seiður (magic, witchcraft, sorcery) in Icelandic, sejd (sorcery, witchcraft, magic potion) in Swedish, and seid (magic) in Norwegian [source].
| Middle Irish (Gaoidhealg) | pis(e)óc = charm, spell, sorcery, witchcraft | 
| Irish (Gaeilge) | piseog = charm, spell, superstition piseogach = practising charms or spells, superstitious
 piseogacht = superstitious practices
 piseogaí = charm-setter, superstitious person
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| Scottish Gaelic (Gàidhlig) | pisreag [ʃiən] = charm, spell, ensorcellment, sorcery, superstition | 
| Manx (Gaelg) | pishag = charm, incantation, spell, witchcraft pishagagh = incantatory, magical, sorcerer, superstitious
 pishagys = enchantment, magic
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| Middle Cornish (Cernewec) | pystyc = witchery, magic, sorcery pystry = witchcraft, magic, sorcery
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| Cornish (Kerneweg) | pystri = magic, sorcery pystrier = sorcerer, warlock, wizard
 pystriores = sorcereress
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Etymology: probably from Latin pyxis (a small box, for holding medicines or toiletries), from Ancient Greek πυξίς (puxís – box, tablet, cylinder), from πῠ́ξος (púxos – boxwood) [source]. The Hibero-English word piseog (an evil spell, curse) comes from the same roots, via Irish [source].
| Old Irish (Goídelc) | airnigde [ˈar͈ʲn͈ʲiɣʲðʲe] = prayer, praying ar·neget = to pray
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| Middle Irish (Gaoidhealg) | airnigde, airnaigde, airna(i)gthe, urnaidhi, urnaith = praying, prayer airnaigid, ernaigit = to pray
 airnaigthech, ernaigtech, urnaigtheach = prayerful, devout
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| Irish (Gaeilge) | urnaí [uːɾˠˈn̪ˠiː / ˈʌɾˠn̪ˠi] = praying, prayer urnaitheach = prayful, devout
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| Scottish Gaelic (Gàidhlig) | ùrnaigh [ur̪ˠn̪ʲɪ] = praying, prayer ùrnaigheach [ur̪ˠn̪ʲijəx] = pertaining to or abounding in prayers
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| Manx (Gaelg) | yeearree = prayer, request, urge, wish, desire, aspiration; to solicit, importune yeearreeagh =  wistful, soliciting, yearning
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Etymology: uncertain [source].
| Middle Irish (Gaoidhealg) | paitir, paidear = the Lord’s Prayer, paternoster | 
| Irish (Gaeilge) | paidir [ˈpˠɑdʲəɾʲ / ˈpˠædʲəɾʲ] = Paternoster, prayer An Phaidir, Paidir an Tiarna = the Lord’s Prayer
 paidreoireacht = praying
 paidrín = Rosary
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| Scottish Gaelic (Gàidhlig) | paidir [padʲɪrʲ] = the Lord’s Prayer, Pater Noster, rosary | 
| Manx (Gaelg) | padjer [ˈpaːʒər] = prayer, devotion Padjer y Çhiarn = the Lord’s Prayer
 goaill padjer = to pray, prayer
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Etymology: from Latin pater (father), the first word of the Lord’s Prayer in Latin (Pater noster) [source].

Sources: Wiktionary, Am Faclair Beag, Online Manx Dictionary, Teanglann.ie, eDIL – Electronic Dictionary of the Irish Language, In Dúil Bélrai English – Old Irish glossary, Geiriadur Prifysgol Cymru, Gerlyver Kernewek, Dictionaire Favereau, TermOfis, English – ProtoCeltic WordList (PDF), Etymological Dictionary Of Proto Celtic