'apotheosis' originates from Greek, specifically the word 'apotheōsis' (ἀποθέωσις), where 'apo-' meant 'away/from' and 'theos' meant 'god' (together implying 'making a god' or 'deification').

'apotheosis' passed into Late Latin as 'apotheosis' and Medieval Latin unchanged, then into Middle French and Middle English; it eventually became the modern English 'apotheosis' (plural 'apotheoses').

Initially it meant 'the act of making someone a god' (deification); over time it broadened to include 'the highest point or culmination' in more figurative uses.