a nosh — a light meal, snack
☛ Yiddish nashn, from Middle High German naschen to eat on the sly

e.g. We just rustled up some nosh
e.g. I'll just have a quick nosh before we go.

a repast — food taken for the occasion of one meal (трапеза, еда);
a light / meager repast — лёгкая закуска
a sumptuous repast (feast) — роскошное угощение

☛ Repast is derived from the Old French repaistre, «to feed.» Repast is a formal term for a meal, whether simple or elegant, and is not much used in modern conversation. Nowadays, it is more of a literary term.

e.g. We usually have a simple repast following our weekly meeting, to spur a sense of comradarie. (meal)
e.g. The elegant repast was carefully put together to celebrate the couple's marriage. (feast, spread)
e.g. Our picnic repast consisted of fruit, cheese, and white wine. (meal)
e.g. My morning repast kept me satiated until lunch. (meal)

a viand — an item of food; especially: a choice or tasty dish (яство)
☛ Middle English, viaunde, from Anglo-French, from Medieval Latin vivanda food, alteration of Latin vivenda, neuter plural of vivendus, gerundive of vivere to live

e.g. a shop selling caviar, foie gras, designer chocolates, and other pricey viands