'apish' originates from English, specifically from the word 'ape' plus the suffix '-ish' (forming adjectives meaning 'like' or 'related to').

'ape' comes from Old English 'apa' (from West Germanic roots). The adjective 'apish' developed by adding the suffix '-ish' to 'ape' in later Middle/early Modern English to mean 'like an ape.'

Initially it meant 'like an ape' in a literal, bodily sense, but over time it acquired the extended sense of 'imitative' or 'foolishly copying' and is often used about mannerisms or behaviour.