If you heard or read that someone had been dobbed in, would you know what that meant?

It’s an expression used mainly in the UK, Australian and New Zealand that means to inform on someone to the authorities – i.e. the police, parents, teachers, etc. For example, if a member of a criminal gang told the police about the illegal activities of the gang, perhaps in the hope of a reduced sentence, or of escaping prosecution altogether, he or she could be said to be dobbing in the other members of the gang.

Other expressions with similar meanings are to grass someone up, and to grass on someone, both of which mean to inform on someone. You could also tell on someone, turn someone in, or report someone. Are there other ways to say the same thing?

According to the Oxford Dictionaries, you can also dob something in, that is “to contribute money to a common cause” (everyone dobbed in a few dollars), and to dob someone in can mean “to impose on someone to do something” (I dobbed him in to do the cleaning). I haven’t heard either of these uses before, have you? Wiktionary states that they are mainly used in Australia, and that to dob someone in can also mean “To nominate a person, often in their absence, for an unpleasant task.” Moreover, a dobber is someone who dobs people in.

The word dob is apparently a dialect word meaning “to put down abruptly” or “to throw something at a target”. The Phrase Finder says that dob might come from the dialects of Kent and/or Nottinghamshire in England, and first appeared in writing in the 1950s. There are also examples of dob in the dialects of Cornwall, Northamptonshire and Cheshire.

A Dictionary of the Kentish Dialect and Provincialisms (1888), defines dob as “to put down [something]”.