'stinking' originates from English, formed by adding the present-participle suffix '-ing' to the verb 'stink', where the verb 'stink' means 'to give off a bad smell'.

'stink' changed from Old English 'stincan' (or 'stincian') and eventually became the modern English word 'stink'; the present-participle pattern '-ing' developed in later Old English/Middle English to form 'stinking'.

Initially, it meant 'to emit a smell' (often a sharp or pungent one); over time the basic sense 'give off an unpleasant smell' has been retained, and it later developed figurative uses (e.g., as an intensifier or to mean 'be very bad').