'asexualise' originates from English formation combining the Greek prefix 'a-' (from Greek 'a-' meaning 'not') and the Latin-derived adjective 'sexual' (from Latin 'sexualis' ultimately from 'sexus' meaning 'sex'), with the verb-forming suffix '-ise' (from French '-iser' via Latin '-izare').

'asexualise' changed from the adjective 'asexual' (formed from 'a-' + 'sexual') by adding the verb suffix '-ise'; 'asexual' itself came into English via Modern Latin and French formation from Greek/Latin elements and eventually produced the verb 'asexualise' in Modern English.

Initially the root 'asexual' meant 'not sexual' or 'lacking sexual characteristics'; over time the verbal form 'asexualise' evolved to mean 'to make non-sexual' or 'to remove sexual qualities or sexualisation'.