jamn.[Per. or Hind. jmah garment, robe.] A kind of frock for children.()n. (Mining) See Jamb.()v. t.[Either fr. jamb, as if squeezed between jambs, or more likely from the same source as champ See Champ.]()1. To press into a close or tight position; to crowd; to squeeze; to wedge in; to cram; as, rock fans jammed the theater for the concert.()The ship . . . jammed in between two rocks. (De Foe.)2. To crush or bruise; as, to jam a finger in the crack of a door.()3. (Naut.) To bring (a vessel) so close to the wind that half her upper sails are laid aback.(W. C. Russell.)4. To block or obstruct by packing too much (people or objects) into; as, shoppers jammed the aisles during the fire sale.()5. (Radio) To interfere with (a radio signal) by sending other signals of the same or nearby frequency; as, the Soviets jammed Radio Free Europe broadcasts for years during the cold war.()6. To cause to become nonfunctional by putting something in that blocks the movement of a part or parts; as, he jammed the drawer by putting in too many loose papers; he jammed the lock by trying to pick it.()v. i.2. To become stuck so as not to function; as, the copier jammed again.()2. (Music) To play an instrument in a jam session.()3. To crowd together; -- usually used with together or in; as, fifty people jammed into a conference room designed for twenty.()n.1. 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.()2. An injury caused by jamming.()3. A difficult situation; as, he got himself into a jam.()n.[Prob. fr. jam, v.; but cf. also Ar. jamad ice, jelly, jmid congealed, jamd congelation, ice.] A preserve of fruit boiled with sugar and water; also called jelly; as, raspberry jam; currant jam; grape jam.()Jam nut. See Check nut, under Check. -- Jam weld (Forging), a butt weld. See under Butt.()