Eid is any day of gathering. It is derived from `Aada (meaning returned), because people return to it periodically. Some scholars say that it derives from `Aadah (custom or practice) because people are accustomed to celebrating it. Its plural is A`yad. Ibnul-`Arabi said:

"It is called Eid because it returns every year with renewed happiness."

Ibn `Aabidayn said:

Eid days are thus named because Allah renews His bounties in them; and He distributes His blessings to His worshippers. Thus on Eidul-Fitr, He permits them to eat after having been restrained from food; and He requires paying sadaqatul-fitr (the charity of breaking the fast) to the needy.

"And on Eidul-Adha, He permits the completion of Hajj (pilgrimage) with the final tawaf (circulating around al-Ka`bah); and He requires offering sacrifices and distributing their meat, etc.

"Also, it is customary for people to be joyful, happy, and to rejoicing during the Eid days."