'appetise' originates from Latin, specifically the verb 'appetere', where the root 'petere' meant 'to seek' or 'to go toward' (combined with the prefix 'ad-/'ap-' giving a sense of 'toward desire').

'appetere' passed into Medieval Latin and Old French forms related to 'appetit-' (cf. French 'appétit'), later forming verbs such as Old French 'apetiser'/'appetiser'; from these the English verb developed as 'appetise' (and by extension the adjective 'appetising').

Initially it related broadly to 'desire' or 'seek after' (in Latin); over time in English it narrowed to the sense of 'stimulating desire for food' or 'making food (or an offer) appealing', which is the primary modern meaning.