The Etymology of Festival
'Festival' descends from Latin 'festum' (feast, holiday), which may trace to a Proto-Indo-European root connected with sacred observance. It entered English in the 14th century as an adjective — a 'festival day' was simply a feast day — before the noun use overtook it. The Latin root spawned an unusually large family in English: 'feast' (via Old French), 'festive,' 'festoon' (garlands hung for celebrations), 'fête' (borrowed directly from French), and Spanish's 'fiesta.' German adopted the root as a suffix that became wildly productive: Oktoberfest, Sängerfest, Turnfest. The word's origin in sacred observance explains why the oldest festivals — Christmas, Easter, Diwali — remain rooted in religious calendars.