'architrave' originates from Italian, specifically the word 'architrave', ultimately from Greek elements where 'arkhi-' meant 'chief' and the element corresponding to 'trabe' meant 'beam'.

'architrave' came into English via Italian 'architrave' and Late Latin forms (e.g. 'architrāvicus'), which themselves derive from Greek compounds such as ἀρχι- (arkhi-, 'chief') + a word for 'beam'; the term entered English through architectural and scholarly usage in the Renaissance and later.

Initially it meant 'chief beam' (the principal beam across columns); over time it also came to mean the decorative moulded frame around doors and windows in general architectural usage.