apt/ept

fit or suited

Spelled apt, ept · aptus 'fitted, suitable'; ept appears in Latin ineptus 'unsuitable'

Latin aptus described something fitted: an apt example fits its subject, aptitude fits someone for a task, and adapting improves the fit.

Words built from it

apt — well suited to the situation
Latin aptus (fitted; suitable) → French apte → apt
aptitude — a natural ability or readiness to learn something
Latin aptus (suited) → aptitudo (fitness) → French aptitude → English aptitude
adapt — change to suit new conditions
Latin ad- (to) + aptare (fit), from aptus (suited) → adaptare → adapt
inept — unskilled or showing poor judgment
Latin in- (not) + aptus (suited), with apt changing to ept → ineptus → inept

rapture — Its apt belongs to a word descended from Latin rapere, 'seize or carry away,' not aptus, 'suited.'