Phrs. 1. Homosexual. See 'bent'. 2. Crooked, dishonest. A catch-phrase whose original meaning was version 2, but with the onset of 'bent' referring to homosexually has come to be heard more with regard to version 1. In British currency, a bob was a slang expression for a shilling (five pence) but with decimalization in 1971 became obsolete. There was never any such thing as a nine bob note, hence the simile. Cf. 'queer as a nine bob note' and 'camp as a row of tents'.
BENT AS A NINE BOB NOTE
Meaning of BENT AS A NINE BOB NOTE in English
Slang English vocab. Английский сленговый словарь. 2012