'apparitional' originates from Latin via Old French and Middle English, specifically from the noun 'apparitio' (Latin) / 'apparition' (Old French, Middle English), where the prefix/root 'ad-' (in compounds) meant 'to/toward' and 'parere' meant 'to appear'.

'apparitional' developed from the Latin noun 'apparitio', which passed into Old French as 'aparition' and then into Middle English as 'apparicioun'/'apparition'; the modern English noun 'apparition' gave rise to the adjective 'apparitional'.

Initially it was tied to the idea of 'an appearance' or 'coming into view' (appearance itself), but over time the derivative adjective came to mean specifically 'relating to or resembling a ghostly appearance'.