a kind of frock for children.-see jamb.-to press into a close or tight position; to crowd; to squeeze; to wedge in.-to crush or bruise; as, to jam a finger in the crack of a door.-to bring (a vessel) so close to the wind that half her upper sails are laid aback.-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.-an injury caused by jamming.-a preserve of fruit boiled with sugar and water; as, raspberry jam; currant jam; grape jam.