- (of food) not thoroughly cooked; not cooked enough.
- Chiefly British. (of meat) rare.
verb (used with or without object), un·der·did, un·der·done, un·der·do·ing.
- to do less or in a lesser fashion than is usual or requisite.
- insufficiently or lightly cooked
adj.1680s, in reference to cooked meat, from under + done.