'autonym' originates from Greek, specifically the word 'autonymos' (from 'auto-' + 'onoma'), where 'auto-' meant 'self' and 'onoma' meant 'name'.

'autonym' passed into New Latin/Modern Latin usage (e.g. 'autonymum') and was borrowed into English in the 19th century, retaining the sense of a 'self-name' and later gaining technical senses in linguistics and taxonomy.

Initially it meant 'a name one uses for oneself' (a 'self-name'); over time the general sense remained but the term became specialized to mean an endonym in linguistics and an automatically established name in biological nomenclature.