'rabbit-haired' originates from Modern English as a compound of 'rabbit' and the past-participle adjective-forming element from 'hair' ('haired'). 'rabbit' in turn comes from Middle English 'rabet', and 'hair' comes from Old English 'hǣr'.

'rabbit' changed from Middle English 'rabet' (borrowed via Anglo-Norman/Old French forms) into the modern English 'rabbit'. 'hair' evolved from Old English 'hǣr' to Middle English 'her(e)' and then modern 'hair', with the adjectival form 'haired' formed in later English; these elements were combined in Modern English to form the descriptive compound 'rabbit-haired'.

Initially the components referred separately to the animal 'rabbit' and the noun 'hair'; combined as a compound the phrase has meant 'having hair like a rabbit' since its formation, and this basic descriptive meaning has been retained.