tuck

Archaic British slang for grub, food, snacks. Packeted food taken along, usually to boarding school for in-between meal time snacking. Usual suspects include picnic or camping foods like biscuits, wafers, crisps, chocolate, sweets, preserves, tinned meats and tinned cakes.

I didn't quite enjoy dinner so it's a good thing I had a bit of spare tuck to tide me over till breakfast.