'ape-likeness' is a Modern English compound formed from 'ape' + the formative suffix '-like' + the nominalizing suffix '-ness'. 'ape' originates from Old English 'apa' meaning 'ape', '-like' comes from Old English 'līc' meaning 'form' or 'body', and '-ness' comes from Old English '-nes(s)e' denoting a state or quality.

'ape' developed from Old English 'apa' into Middle English 'ape' and remained the word for the animal; the adjective-forming element '-like' (from 'līc') has been used since Old English to mean 'having the form of', and '-ness' was added to create abstract nouns, producing 'ape-likeness' in Modern English by straightforward compounding.

Initially, the components referred simply to 'the animal' (for 'ape') and 'form/quality' (for '-like' and '-ness'); over time the compound came to specifically denote the abstract quality 'resemblance to an ape', a meaning consistent with its parts.