'unforested' originates from English, formed by the negative prefix 'un-' (meaning 'not') + the noun 'forest' + the adjectival suffix '-ed'; 'forest' itself comes from Old French 'forest' (from Medieval Latin 'foresta').

'forest' entered Middle English from Old French 'forest', which in turn traces to Medieval Latin 'foresta'. The productive English prefix 'un-' (Old English origin) was combined with 'forest' plus '-ed' to form the modern adjective 'unforested' in modern English usage.

Initially 'forest' (from medieval usage) referred to an area set aside or 'outside' land and later came to mean 'a large area covered with trees'; 'unforested' therefore evolved to mean 'not covered with forest' in modern usage.