'spider-shaped' is a modern English compound formed from 'spider' + 'shaped'. 'spider' originates from Old English (recorded as 'spīthra'/'spīþra'), where the root was associated with 'spinner' (related to the verb 'to spin'). 'shape' originates from Old English 'sceap' (or 'gesceap'), meaning 'form' or 'creation'.

'spider' evolved from Old English 'spīthra' into Middle English forms like 'spydre'/'spider' and eventually the modern English 'spider'. 'shape' came from Old English 'sceap'/'gesceap' to Middle English 'shape' and then to modern English 'shape'. The compound 'spider-shaped' is formed in modern English by combining the noun and the past-participle adjective 'shaped'.

Individually, 'spider' originally emphasized the creature noted for spinning, and 'shape' meant 'form'; together in modern usage they mean 'having the form or appearance of a spider' with little semantic shift from the component senses.