See Also:

jam(4) (iou)



jam noun4. E19.
[from JAM verb1.]
The action of jamming; the fact or condition of being jammed; a crush, a squeeze; a mass of things or persons crowded together or interlocked so as to prevent individual movement; spec. such an accumulation of logs in a river or traffic in a street. E19.
log jam, traffic jam, etc.
b. fig. An awkward or difficult situation. E20.
P. H. Gibbs 'I'm in the devil of a jam,' said Robin gloomily.
The action or an act of jamming radio, radar, etc., signals. E20.
Jazz or popular music simultaneously improvised by a number of performers; a period of playing such music, an informal gathering of musicians improvising together (also jam session). colloq. E20.
Southern Rag Meadowcroft fetched his instrument and joined in an impromptu jam session.
Comb.: jam-proof adjective protected against jamming; jam session: see sense 3 above; jam-up colloq. = sense 1 above.