'Occidental-themed' is a modern English compound of 'Occidental' and 'themed'. 'Occidental' originates from Latin, specifically the word 'occidens' (from the verb 'occidere'), where 'occidere' meant 'to fall, to set (as the sun)' and 'occidens' came to mean 'west'. 'Theme' (→ 'themed') originates from Greek 'thema' via Latin/Old French, where 'thema' meant 'that which is laid down' or 'subject'.

'Occidental' developed in English from Latin 'occidens' → Old French/Medieval Latin forms → English 'Occident' and the adjective 'Occidental'. 'Theme' came from Greek 'thema' → Latin/Old French 'theme' → Modern English 'theme', and 'themed' is the past-participial/derivative adjective form. These elements were combined in English as the compound adjective 'Occidental-themed'.

Initially, 'Occidental' meant simply 'of or relating to the west (where the sun sets)', and 'theme' meant 'subject' or 'topic'. Over time the compound 'Occidental-themed' came to mean specifically 'styled or designed around Western (Occidental) motifs or subject matter.'