festival (n.)
1580s, "a festal day, appointed day of festive celebration," short for festival day (late 14c.), from Old French festival (adj.) "suitable for a feast; solemn, magnificent, joyful, happy," and directly from Medieval Latin festivalis "of a church holiday," from festum "festival, holiday," neuter of festus "of a feast" (see feast (n.)). The English word returned to French 19c. in certain specialized senses.