1. to drive or wedge forcibly into a tight position: jammed the cork in the bottle.
2. to activate or apply (a brake) suddenly. often used with on: jammed the brakes on.
3. to cause (moving parts, for example) to lock into an unworkable position: jammed the typewriter keys.
4. to pack (items, for example) to excess; cram: jammed my clothes into the suitcase.
5. to fill (a container or space) to overflowing: I jammed the suitcase with clothes. fans jammed the hallway after the concert.
6. to block, congest, or clog: a drain that was jammed by debris.
7. to crush or bruise: jam a finger.
8. electronics to interfere with or prevent the clear reception of (broadcast signals) by electronic means.
9. baseball to throw an inside pitch to (a batter), especially to prevent the batter from hitting the ball with the thicker part of the bat.
10. to become wedged or stuck.
11. to become inoperable: the computer keyboard jammed.
12. to force one's way into or through a limited space.
13. music to participate in a jam session.
14. basketball to make a dunk shot.
15. the act of jamming or the condition of being jammed.
16. A crush or congestion of people or things in a limited space: a traffic jam.
17. A trying situation. see synonyms at predicament.
18. A preserve made from whole fruit boiled to a pulp with sugar.

1. A sweet mixture of fruit boiled with sugar and allowed to congeal. often spread on bread or toast or used in jam tarts.
2. A difficult situation.
3. blockage, congestion.
4. (popular music) an informal, impromptu performance or rehearsal.
5. (baseball) A difficult situation for a pitcher or defending team.
6. (basketball) A forceful dunk.
7. (roller derby) A play during which points can be scored.
8. any of several rock-climbing maneuvers requiring wedging of an extremity into a tight space.
9. luck.
10. to get something stuck in a confined space.
11. to brusquely force something into a space; cram, squeeze.
12. to cause congestion or blockage. often used with "up"
13. to block or confuse a broadcast signal.
14. to throw a pitch at or near the batter's hands.
15. to play music (especially improvisation as a group.)
16. to injure a finger or toe by sudden compression of the digit's tip.
17. to attempt to score points.

1. A kind of frock for children.
2. see jamb.
3. A mass of people or objects crowded together; also, the pressure from a crowd; a crush
4. an injury caused by jamming.
5. A difficult situation.
6. A preserve of fruit boiled with sugar and water; also called jelly
7. to become stuck so as not to function.
8. to play an instrument in a jam session.
9. to crowd together; -- usually used with together or in.
10. to press into a close or tight position; to crowd; to squeeze; to wedge in; to cram.
11. to crush or bruise.
12. to bring (a vessel) so close to the wind that half her upper sails are laid aback.
13. to block or obstruct by packing too much (people or objects) into.
14. to interfere with (a radio signal) by sending other signals of the same or nearby frequency.
15. to cause to become nonfunctional by putting something in that blocks the movement of a part or parts.

1. to press; squeeze; thrust or press down or in with force or violence; thrust or squeeze in so as to stick fast; press or crowd in such a manner as to prevent motion or hinder extrication.
2. to fill full; block up; prevent the movement of by pressure, crowding, etc.
3. to tread hard or make firm by treading, as land is trodden hard by cattle.
4. to become wedged together or in place, as by violent impact; stick fast: as, the door jams.
5. to push (a bill or measure) through the regular routine of a legislative body by the brute force of a majority controlled by ‘the machine,’ without proper consideration or discussion. [political slang.]
6. to smear or spread with jam: as, a slice of bread thickly jammed.
7. to become jam; thicken to the consistency of jam.
8. A crush; a squeeze; pressure by thrusting or crowding.
9. A crowd of objects irregularly and tightly pressed together by arrest of their movement; a block, as of people, vehicles, or floating logs.
10. A conserve of fruits prepared by boiling them to a pulp in water with sugar.
11. another spelling of jamb, 4.
12. an extra pool in the game of napoleon.
13. the title of certain native chiefs in northwestern india.
14. in england, a kind of dress worn by children: so called from the hindu jama, a long muslin gown worn in india by both Mohammedans and hindus.
15. an abbreviation of jamaica.

1. crush or bruise
2. crowd or pack to capacity
3. informal terms for a difficult situation
4. deliberate radiation or reflection of electromagnetic energy for the purpose of disrupting enemy use of electronic devices or systems
5. press tightly together or cram
6. get stuck and immobilized
7. a dense crowd of people
8. push down forcibly
9. interfere with or prevent the reception of signals
10. block passage through
11. preserve of crushed fruit