ex ungue leonem (L.), [judge] the lion from his claws.
ex uno disce omnes (L.), from one example learn what they all are.
ex utraque parte (L.), on either side.
ex voto (L.), according to one's prayer, by reason of a vow: votive: a votive offering.
faber est quisque fortunæ suæ (L.), every man is the fashioner of his own fortune.
fable convenue (Fr.), fable agreed upon—Voltaire's name for history.
facile est inventis addere (L.), it is easy to add to things invented already.
facile princeps (L.), obviously pre-eminent: an easy first.
facilis descensus Averno (or Averni) (L.), descent to Avernus (hell) is easy: the road to evil is easy.
facinus majoris abollæ (L.), the crime of a larger cloak, i.e. of a deep philosopher.