Definition of jam

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