'reptile-like' originates from Latin and Old English, specifically the Latin word 'reptilis' and the Old English word 'līc', where 'reptilis' meant 'creeping' and 'līc' meant 'having the form of (or like)'.

'reptile' comes from Latin 'reptilis' (meaning 'creeping'), entered English via Medieval/Modern Latin and Old French influences to become 'reptile' in English; the suffix '-like' comes from Old English 'līc' which developed into the productive Modern English adjectival suffix '-like'; together they formed the compound adjective 'reptile-like' to mean 'having the qualities of a reptile'.

Initially, 'reptilis' meant 'creeping' and '-līc' meant 'having the form of'; over time the compound came to mean 'resembling a reptile' in appearance or behavior and was extended metaphorically to describe cold, unemotional, or sly characteristics.