Other forms: festivities
Festivity is joyful activity that marks a special occasion. An air of festivity, the festivities began, join the festivities.
The plural festivities means the events themselves and is far commoner than the singular, which means the mood. It comes from the same Latin as feast and festival, all from a word meaning a holy day set aside.
1nounfestivityJoyful activity that marks a special occasion.
“The whole town joined in the festivities, with music and fireworks late into the night.”
festivity is a celebration.
Latin festivitas comes from festivus, festive, from festum, a feast day.
Latin
festīvitas
Middle French
festivité
Middle English
festivite
English, today
festivity
Middle English festivite, from Middle French festivité, from Latin festīvitas, equivalent to festive + -ity.
Etymology from Wiktionary, CC BY-SA