Green’s Dictionary of Slang

feevee n.

[pron. of SE]

(US) $5.

[US]R. Lardner ‘The Facts’ in Coll. Short Stories (1941) 466: Billy [...] located his pocketbook. In it were two fives and a ten. ‘I gotta have a feevee,’ he said. ‘All right, I’ll get something for fifteen.’.