(British exclamation)

Excellent, fine, the real thing. An all-purpose term of approbation increasingly heard among working-class Londoners in the 1980s, probably derived from 'bona fide' or from the Spanish and Italian words for good (buena and buona). In the 1960s bona was part of the camp lexicon (popularised in Kenneth Horne's radio comedy shows), originating in theatrical performers' and prostitutes' argot of the 19th century, in which it often meant 'beautiful'.

a bona geezer.