'cave-adapted' originates from modern English as a compound of 'cave' and the past participle 'adapted' (from the verb 'adapt').

'cave' comes from Latin 'cavus' meaning 'hollow', passing into Old French and then Middle English as 'cave'; 'adapt' derives from Latin 'adaptāre' (ad- 'to/toward' + aptāre 'fit'), with past participle forms (e.g. Latin 'adaptātus') contributing to English 'adapted'. The compound 'cave-adapted' is a descriptive formation in modern biological English.

Individually, 'cave' meant 'hollow' and 'adapt' meant 'to make fit'; combined as 'cave-adapted' the phrase specifically denotes organisms made or having become suited for life in caves.