banyan day

Etymology
According to the OED, the term is borrowed from the Banyans in the East Indies, a caste that ate nothing that had life.

Noun

 * 1)  In British naval tradition, a day of the week when galley kitchens served no meat on board ship.
 * 2)  A picnic or cookout for the ship's crew.
 * 1)  A picnic or cookout for the ship's crew.

Alternative forms

 * ,, banian-day