JIMMY A LOCK

[Q] From Steven Shumak in Toronto: I am curious about the origin of the word jimmy, as in to jimmy a lock. Does the expression derive from a nimble-fingered fellow named James, or does it have nothing to do with the Christian name James?

[A] The British English term for the housebreaker’s implement was usually jemmy, still common here and also in Australia and New Zealand. Authorities are fairly sure that this word — and the verb to jemmy or to jimmy derived from it — did come from a familiar form of James, though precisely why seems likely to remain for ever a mystery. There seems to be a strong tradition of giving tools the names of people. Another thieves’ term for a short iron bar used to force locks or break open doors was bess; yet another was billy. Think of the jack you use to lift the car when you’re replacing a wheel — this seems to be from the familiar form of John. Yet another example is the term derrick for a type of crane, named after a famous early seventeenth-century hangman.

World Wide Words is copyright © Michael Quinion, 1996–2009. All rights reserved. Contact me if you want to reproduce this piece, but first see my advice page, which also has notes about linking. Your comments and corrections are welcome.