n.1 Brit. hist. the sum of 21 old shillings ({pound}1.05), used esp. in determining professional fees.
2 hist. a former British gold coin worth 21 shillings, first coined for the African trade.
Phrases and idioms:
guinea-fowl any African fowl of the family Numididae, esp. Numida meleagris, with slate-coloured white-spotted plumage. guinea-pig
1. a domesticated S. American cavy, Cavia porcellus, kept as a pet or for research in biology etc.
2 a person or thing used as a subject for experiment.
Etymology: Guinea in W. Africa