pump¹ (pŭmp)
n.

1. A machine or device for raising, compressing, or transferring fluids.
2. Physiology. A molecular mechanism for the active transport of ions or molecules across a cell membrane.
3. Physics. Electromagnetic radiation used to raise atoms or molecules to a higher energy level.
4. Informal. The heart.

v., pumped, pump·ing, pumps.

v.tr.

1. To raise or cause to flow by means of a pump.
2. To draw, deliver, or pour forth as if with a pump.
3. To remove the water from: pump out a flooded basement.
4. To cause to move with the up-and-down motion of a pump handle: a bicyclist pumping the pedals.
5. To propel, eject, or insert with or as if with a pump: pumped new life into the economy.
6. Physics. To raise (atoms or molecules) to a higher energy level by exposing them to electromagnetic radiation at a resonant frequency.
7. Physiology. To transport (ions or molecules) against a concentration gradient by the expenditure of chemically stored energy.
8. To question closely or persistently: pump a witness for secret information.

v.intr.

1. To operate a pump.
2. To raise or move gas or liquid with a pump.
3. To move up and down in the manner of a pump handle.
4. Sports. To fake a throw, pass, or shot by moving the arm or arms without releasing the ball.

phrasal verb:

pump up

1. To inflate with gas by means of a pump: pump up a tire.
2. Slang. To fill with enthusiasm, strength, and energy: The lively debate really pumped us up.
3. Sports. To be actively involved in a bodybuilding program: athletes pumping up at the gym.

idiom:

pump iron Sports.

1. To lift weights.

[Middle English pumpe.]

pumper pump'er n.

pump² (pŭmp)
n.
A woman's shoe that has medium or high heels and no fastenings.

[Origin unknown.]

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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