jam

[[t]ʤæ̱m[/t]]

jams, jamming, jammed

1) N-MASS Jam is a thick sweet food that is made by cooking fruit with a large amount of sugar, and that is usually spread on bread. [mainly BRIT]

...home-made jam.

(in AM, usually use jelly)

2) VERB If you jam something somewhere, you push or put it there roughly.

[V n prep] He picked his cap up off the ground and jammed it on his head...

[V n prep] Pete jammed his hands into his pockets.

3) V-ERG If something such as a part of a machine jams, or if something jams it, the part becomes fixed in position and is unable to move freely or work properly.

The second time he fired his gun jammed...

[V n] A rope jammed the boat's propeller...

[V adj] Cracks appeared in the wall and a door jammed shut...

[be V-ed adj] The intake valve was jammed open...

[V-ed] Every few minutes the motor cut out as the machinery became jammed. [Also V n adj]

4) VERB If vehicles jam a road, there are so many of them that they cannot move.

[V n] Hundreds of departing motorists jammed roads that had been closed during the height of the storm.

Derived words:

jammed ADJ-GRADED oft ADJ with n

Nearby roads and the dirt track to the beach were jammed with cars.

N-COUNT

Jam is also a noun.

400 trucks may sit in a jam for ten hours waiting to cross the limited number of bridges.

5) VERB If a lot of people jam a place, or jam into a place, they are pressed tightly together so that they can hardly move.

[V n] Hundreds of people jammed the boardwalk to watch...

[V into n] They jammed into buses provided by the Red Cross and headed for safety.

Syn:

cram

Derived words:

jammed ADJ-GRADED

The stadium was jammed and they had to turn away hundreds of disappointed fans.

6) VERB To jam a radio or electronic signal means to interfere with it and prevent it from being received or heard clearly.

[V n] They will try to jam the transmissions electronically.

Derived words:

jamming N-UNCOUNT usu with supp

The plane is used for electronic jamming and radar detection.

7) VERB If callers are jamming telephone lines, there are so many callers that the people answering the telephones find it difficult to deal with them all.

[V n] Hundreds of callers jammed the BBC switchboard for more than an hour...

[V-ed] The telephone exchange has been jammed all day with people wanting to buy season tickets.

8) N-SING: in N If someone is in a jam, they are in a very difficult situation. [INFORMAL]

They were in a real jam, Bob thought glumly.

9) VERB When jazz or rock musicians are jamming, they are informally playing music that has not been written down or planned in advance. [INFORMAL]

He was jamming with his saxophone.

N-COUNT

Jam is also a noun.

...a free-form jazz jam. ...a jam session.

10) → See also traffic jam