'appetite-suppressant' originates from modern English, specifically a compound of the words 'appetite' and 'suppressant'. 'appetite' ultimately comes from Latin 'appetitus', where 'ad-' (or 'ap-') meant 'toward' and 'petere' meant 'to seek or strive for'; 'suppressant' comes from Latin 'supprimere', where 'sub-' meant 'under' and 'premere' meant 'to press.'

'appetite' changed from Latin 'appetitus' to Old French 'apetit' and then into Middle and modern English as 'appetite'. 'suppressant' developed from Latin 'supprimere' through Old French/French forms (e.g. 'supprimer', participial/adjectival forms) and entered English as 'suppressant' (the agent/adjectival form).

Initially, 'appetite' meant 'a striving after or desire' and 'suppressant' meant 'that which presses down'; over time the compound came to mean 'a substance that reduces the desire to eat.'