American English

Definition of jam verb from the Oxford Advanced American Dictionary



    Verb Forms present simple I / you / we / they jam
    he / she / it jams
    past simple jammed
    -ing form jamming
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    push with force
  1. 1[transitive] jam something + adv./prep. to push something somewhere with a lot of force He jammed his fingers in his ears. A stool had been jammed against the door.
  2. stop moving/working
  3. 2[intransitive, transitive] to become unable to move or work; to make something do this jam (up) The photocopier keeps jamming up. jam something (up) There's a loose part that keeps jamming the mechanism. + adj. The valve has jammed shut. jam something + adj. He jammed the door open with a piece of wood.
  4. put into small space
  5. 3[transitive, intransitive] to put someone or something into a small space where there is very little room to move synonym squash, squeeze jam somebody/something + adv./prep. Six of us were jammed into one small car. We were jammed together like sardines in a can. The cabinets were jammed full of old newspapers. + adv./prep. Nearly 1,000 students jammed into the hall. see also jam-packed
  6. fill with people/things
  7. 4[transitive] jam something (up) (with somebody/something) to fill something with a large number of people or things so that it is unable to function as it should synonym block Viewers jammed the switchboard with complaints.
  8. radio broadcast
  9. 5[transitive] jam something (technology) to send out radio signals to prevent another radio broadcast from being heard
  10. play music
  11. 6[intransitive, transitive] jam (something) to play music with other musicians in an informal way without preparing or practicing first
  12. Idioms
    jam on the brake(s), jam the brake(s) on
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    to operate the brake or brakes on a vehicle suddenly and with force The car skidded as he jammed on the brakes.
See the Oxford Advanced Learner's Dictionary entry: jam