v. t. [ imp. & p. p. Jammed p. pr. & vb. n. Jamming. ] [ Either fr. jamb, as if squeezed between jambs, or more likely from the same source as champ See Champ. ] [ 1913 Webster ]

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. [ 1913 Webster ]

The ship . . . jammed in between two rocks. De Foe. [ 1913 Webster ]

2. To crush or bruise; as, to jam a finger in the crack of a door. [ Colloq. ] [ 1913 Webster ]

3. (Naut.) To bring (a vessel) so close to the wind that half her upper sails are laid aback. W. C. Russell. [ 1913 Webster ]

4. To block or obstruct by packing too much (people or objects) into; as, shoppers jammed the aisles during the fire sale. [ PJC ]

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. [ PJC ]

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. [ PJC ]

n. [ Per. or Hind. jāmah garment, robe. ] A kind of frock for children. [ 1913 Webster ]

n. (Mining) See Jamb. [ 1913 Webster ]

n. [ Prob. fr. jam, v.; but cf. also Ar. jamad ice, jelly, jāmid congealed, jamd congelation, ice. ] A preserve of fruit boiled with sugar and water; also called jelly; as, raspberry jam; currant jam; grape jam. [ 1913 Webster ]

Jam nut. See Check nut, under Check. --
Jam weld (Forging), a butt weld. See under Butt. [ 1913 Webster ]

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. [ 1913 Webster ]

2. An injury caused by jamming. [ Colloq. ] [ 1913 Webster ]

3. A difficult situation; as, he got himself into a jam. [ informal ] [ PJC ]

v. i. 2. To become stuck so as not to function; as, the copier jammed again. [ PJC ]

2. (Music) To play an instrument in a jam session. [ PJC ]

3. To crowd together; -- usually used with together or in; as, fifty people jammed into a conference room designed for twenty. [ PJC ]

‖n. [ NL. ] Jamaicine. [ 1913 Webster ]

‖n. Same as Jemidar. [ 1913 Webster ]

n. One of the West Indian islands. [ 1913 Webster ]

Jamaica ginger, a variety of ginger, called also white ginger, prepared in Jamaica from the best roots, which are deprived of their epidermis and dried separately. --
Jamaica pepper, allspice. --
Jamaica rose (Bot.), a West Indian melastomaceous shrub (Blakea trinervis), with showy pink flowers. [ 1913 Webster ]

a. Of or pertaining to Jamaica. -- n. A native or inhabitant of Jamaica. [ 1913 Webster ]