'athenaeum' originates from Latin, specifically the word 'Athenaeum', which was borrowed from Greek 'Athēnaîon' (Ἀθηναῖον), where 'Athēnai' meant 'Athens' (i.e. relating to Athena).

'athenaeum' changed from the Latin word 'Athenaeum' (used in Late Latin to denote a school or institution associated with learning) and entered English via modern borrowings from Latin and French, eventually becoming the modern English word 'athenaeum'.

Initially, it meant 'a temple or place associated with Athena (or a school of learning)', but over time it evolved into its current sense of 'a library or an institution for literary or scientific study'.