'appositeness' originates from Latin, specifically the word 'appositus', where 'ad-' (in the compound) meant 'to/toward' and 'ponere' meant 'to place'.

'appositeness' developed from the adjective 'apposite', which came into English via Medieval Latin 'appositus' (past participle of 'apponĕre'/'adponĕre') and Old/Medieval French forms related to 'apposer', eventually yielding the modern English 'apposite' and its noun derivative 'appositeness'.

Initially it conveyed the sense of 'placed near' or 'put next to' (a spatial sense), but over time it evolved to mean 'fitting, suitable, or relevant'—the sense reflected in the modern word 'appositeness'.