far niente (It.), doing nothing.
farceur (Fr.), a wag, a joker.
farouche (Fr.), sullen, savage.
farrago libelli (L.), a medley of miscellaneous topics for a little book [of satire].
fas est et ab hoste doceri (L.), it is right to be taught even by an enemy.
Fata obstant (L.), the Fates oppose it.
Fata viam invenient (L.), the Fates will find out a way.
faute de mieux (Fr.), for want of better.
faux pas (Fr.), a false step: a mistake.
favete linguis (L.), favour me with your tongues—keep a discreet silence.