Definition of Jam

Verb: jam (jammed,jamming) jam

Press tightly together or cram
"The crowd jammed the auditorium";
- throng, mob, pack, pile
Push down forcibly
"The driver jammed the brake pedal to the floor"
Hurt or bruise with a squashing force
"jam a toe";
- crush
Interfere with or prevent the reception of signals
"Jam the Voice of America";
- block
Get stuck and immobilized
"the mechanism jammed"
Crowd or pack to capacity
"the theatre was jammed";
- jampack, ram, chock up, cram, wad
Block passage through
"jam the path";
- obstruct, obturate, impede, occlude, block, close up
(popular music) play music in a group, esp. improvising

Noun: jam jam

Preserve of crushed fruit
Informal term for a difficult situation
"he got into a terrible jam";
- fix, hole, mess, muddle, pickle, kettle of fish
A dense crowd of people
- crush, press
Deliberate radiation or reflection of electromagnetic energy for the purpose of disrupting enemy use of electronic devices or systems
- jamming, electronic jamming
(popular music) an informal, impromptu performance or rehearsal