An important or large meal (or series of meals) done in celebration of something or as a reminder of some past event. A feast could be a solemn remembrance or a celebration. Feasts often spanned multiple days and were similar to festivals.
Key passages
Tob 2:1–2

When I returned to my house and when Hannah my wife was restored to me with Tobias my son on the feast of Pentecost, (which is the holy Feast of Seven Weeks), there was a good dinner prepared for me, and I reclined to eat. And I saw a numerous variety of dishes and said to my son, “Go and …

Jdt 1:16

Then he and his army returned with them for one hundred twenty days.

Jdt 6:21

And Uzziah took him from the assembly into his house and gave a banquet for the elders, and they called upon the God of Israel for help that whole night.

Jdt 13:1

And when evening had come, his slaves made haste to depart; and Bagoas closed the tent from outside and shut off the attendants from the face of his lord. Then they departed for their beds, for they were all weary since the drinking party had been going on for a long time. …

Gk Es 14:17

And your servant has not eaten at Haman’s table, and I have not honored the feast of the king, nor have I drunk the wine of libations.