noun an injury caused by jamming.
2. jam ·noun a kind of frock for children.
3. jam ·noun ·see jamb.
4. jam ·vt to crush or bruise; as, to jam a finger in the crack of a door.
5. jam ·vt to bring (a vessel) so close to the wind that half her upper sails are laid aback.
6. jam ·noun a preserve of fruit boiled with sugar and water; as, raspberry jam; currant jam; grape jam.
7. jam ·vt to press into a close or tight position; to crowd; to squeeze; to wedge in.
8. jam ·noun a mass of people or objects crowded together; also, the pressure from a crowd; a crush; as, a jam in a street; a jam of logs in a river.