'apardon' originates from Middle English, specifically formed with the prefix 'a-' + the word 'pardon' (from Old French 'pardoner'), where the prefix 'a-' was a verbal/formative element and 'pardoner' came from Latin 'perdonare' meaning 'to completely give/forgive'.

'apardon' developed in Middle English as a verbal form related to 'pardon' (Old French 'pardoner'), which itself comes from Latin 'perdonare'; the element 'per-'/ 'per-' and 'donare' ('to give') in Latin transformed through Old French into the verb meaning 'to forgive', and Middle English used forms such as 'apardon' in literary and colloquial contexts.

Initially it meant 'to grant a pardon' or 'to forgive' in much the same sense as 'pardon'; over time the standalone form 'apardon' became archaic and the modern verb 'pardon' became the standard form.