'autotomise' originates from Greek via New/Modern Latin, specifically the Greek compound 'autotomia' where 'auto-' meant 'self' and 'tomē' (from 'temnein') meant 'a cutting' or 'to cut'.

'autotomia' (Greek) passed into Late/Medieval Latin and New Latin as 'autotomia' and into English as the noun 'autotomy'; the verb form was later formed in English as 'autotomize' (US) and 'autotomise' (UK).

Initially it meant 'self-cutting' (the act of cutting oneself off), and over time it retained this biological sense of 'self-amputation' used to describe animals shedding body parts.