Noun | 1. | sixpence - a small coin of the United Kingdom worth six pennies; not minted since 1970 Britain, Great Britain, U.K., UK, United Kingdom, United Kingdom of Great Britain and Northern Ireland - a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland; `Great Britain' is often used loosely to refer to the United Kingdom coin - a flat metal piece (usually a disc) used as money |