jam 1 (jăm)
v. jammed, jam·ming, jams
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.
a. To cause to become unworkable because a part is stuck: The wrinkled paper jammed the copying machine.
b. To cause (moving parts, for example) to lock into an unworkable position: jammed the typewriter keys.
a. To pack (items, for example) to excess; cram: jammed my clothes into the suitcase.
b. To fill (a container or space) to overflowing: I jammed the suitcase with clothes. Fans jammed the hallway after the concert.
5. To block, congest, or clog: a drain that was jammed by debris.
6. To crush or bruise: jam a finger.
7. Electronics To interfere with or prevent the clear reception of (broadcast signals) by electronic means.
8. 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.
1. To become wedged or stuck: The coin jammed in the slot.
2. To become locked or stuck in an unworkable position: The computer keyboard jammed.
3. To force one's way into or through a limited space: We all jammed into the elevator.
4. Music To participate in a jam session.
5. Basketball To make a dunk shot.
1. The act of jamming or the condition of being jammed.
2. A crush or congestion of people or things in a limited space: a traffic jam.
3. A trying situation. See Synonyms at predicament.
4. See jam session.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.