'asexual' originates from New Latin 'asexualis', where the prefix 'a-' meant 'not' (from Greek) and 'sexualis' related to Latin 'sexus' meaning 'sex'.

'asexual' entered English in the 19th century from Modern/Neo-Latin 'asexualis', which itself was built from Greek/Latin elements ('a-' + 'sexualis').

Initially, it referred broadly to 'not sexual' or 'without sex' (often in biological contexts). Over time it also came to denote the sexual orientation of people who do not experience sexual attraction.