'appetite-lowering' is a modern English compound formed from the noun 'appetite' and the present-participle/gerund 'lowering'. 'appetite' originates from Latin, specifically the word 'appetitus' (from the verb 'appetere'), where 'appetere' meant 'to desire' or 'to seek'. 'lowering' derives from the verb 'lower' (of Old English origin) plus the suffix '-ing'.

'appetite' passed into Middle English via Old French 'appetit' from Latin 'appetitus' and developed into the modern English 'appetite'. The verb 'lower' has been used in English since Old/Middle English to mean 'to make less high' or 'to reduce'. The compound 'appetite-lowering' arose in modern English (late 19th to 20th century) to describe substances or effects that reduce appetite.

Initially 'appetite' meant a general 'desire' (from Latin); over time its sense narrowed in English to primarily mean 'desire for food'. Combined with 'lowering', the compound came to mean 'causing a reduction in the desire to eat'.