'apologiser' originates from late Modern English, specifically the verb 'apologise' combined with the agent suffix '-er', where the Greek root 'apologia' meant 'a speech in defense'.

'apologiser' developed via the verb 'apologise' which came into English from Old French/Latin forms ultimately from Greek 'apologia' (ἀπολογία); the verb 'apologise' (Late Middle English) later produced the agent noun with '-er' to form 'apologiser'.

Initially the root 'apologia' meant 'a formal defense or speech in defense', but over time the verb 'apologise' shifted to mean 'to express regret', and 'apologiser' now means 'one who expresses regret (says sorry)'.