'arboricolous' originates from Latin, specifically the word 'arbor', where 'arbor' meant 'tree' and the suffix '-colous' derives from Latin 'colere' meaning 'to inhabit or dwell'.

'arboricolous' changed from Neo-Latin/Scientific Latin form 'arboricolus' (or formed by combining Latin elements 'arbor' + '-colous') and was adopted into modern English as 'arboricolous'.

Initially it meant 'inhabiting trees' in scientific/Latin-derived usage, and this core meaning has been retained in modern English.