'skull-like' originates from English, specifically the word 'skull' and the suffix '-like', where 'skull' ultimately derives from Old Norse 'skalli' meaning 'bald head' and the element '-like' comes from Old English 'lic' meaning 'having the form of'.

'skull' changed from Old Norse 'skalli' into Middle English forms such as 'scul' or 'skulle' and eventually became the modern English word 'skull'. The adjective-forming element '-like' evolved from Old English 'lic' (later Middle English '-like') to the productive modern suffix '-like'.

Initially related to the idea of a 'bald head' (from 'skalli'), the sense shifted to the bone structure of the head and then to the broader descriptive use 'resembling a skull'; '-like' retained its meaning 'having the form of'.