ETYM Old Eng. feste festival, holiday, feast, Old Fren. feste festival, French fęte, from Latin festum, pl. festa, from festus joyful, festal; of uncertain origin. Related to Fair, Festal, Fęte.
Something experienced with great delight.

ETYM Neut. sing. of Latin magnus great.
A large bottle for liquor or wine.
Bottle holding twice as much as an ordinary bottle; large-caliber or more than usually powerful firearm. magnum opus, Latin, “great work”; finest achievement, especially literary.