1. Not used up; SYN. left over, left, odd, remaining, unexpended.
2. Uneaten and saved for eating later; SYN. cooked-over, warmed-over, reheated.
3. Something that is left over remains after people have used or taken as much of it as they need or want.

A small part or portion that remains after the main part no longer exists; SYN. remnant.