An example of jail is to put someone in a holding cell after they've committed a crime.
An example of a jail is San Quentin Prison.
Origin of jail
- From Middle English jaiole (from Old French) and from Middle English gaiol, gaol (from Old North French gaiole) both from Vulgar Latin gaviola from Latin caveola diminutive of cavea cage, hollow
From American Heritage Dictionary of the English Language, 5th Edition