'spiderlike' originates from English, specifically the combination of the word 'spider' and the suffix '-like', where 'spider' meant the arachnid and '-like' meant 'having the characteristic of'.

'spider' comes from Old English (e.g. 'spīthra' or similar forms) and developed into Middle English 'spider'; the adjectival suffix '-like' developed from Old English '-lic' (later Middle English '-like') and combined with nouns to form adjectives (e.g. 'spider' + '-like' → 'spiderlike').

Initially it was a straightforward compound meaning 'like a spider' (literal resemblance); over time it has retained that literal sense and also come to be used figuratively for anything that suggests spiderlike qualities.