v. lost (lôst, lŏst), los·ing, los·es
1. To be unsuccessful in retaining possession of; mislay: He's always losing his car keys.
a. To be deprived of (something one has had): lost her art collection in the fire; lost her job.
b. To be left alone or desolate because of the death of: lost his wife.
c. To be unable to keep alive: a doctor who has lost very few patients.
3. To be unable to keep control or allegiance of: lost his temper at the meeting; is losing supporters by changing his mind.
4. To fail to win; fail in: lost the game; lost the court case.
5. To fail to use or take advantage of: Don't lose a chance to improve your position.
6. To fail to hear, see, or understand: We lost the plane in the fog. I lost her when she started speaking about thermodynamics.
a. To let (oneself) become unable to find the way.
b. To remove (oneself), as from everyday reality into a fantasy world.
8. To rid oneself of: lost five pounds.
9. To consume aimlessly; waste: lost a week in idle occupations.
10. To wander from or become ignorant of: lose one's way.
a. To elude or outdistance: lost their pursuers.
b. To be outdistanced by: chased the thieves but lost them.
12. To become slow by (a specified amount of time). Used of a timepiece.
13. To cause or result in the loss of: Failure to reply to the advertisement lost her the job.
14. To cause to be destroyed. Usually used in the passive: Both planes were lost in the crash.
15. To cause to be damned.
1. To suffer loss: investors who lost heavily on the firm's stock.
2. To be defeated: Our team lost in overtime.
3. To operate or run slow. Used of a timepiece.
To fail to achieve or receive an expected gain.
lose it Slang
1. To become very angry or emotionally upset.
2. To become deranged or mentally disturbed.
3. To become less capable or proficient; decline: He can still play tennis well. He hasn't lost it yet.
lose out on
To miss (an opportunity, for example).
1. To operate too slowly. Used of a timepiece.
2. To delay advancement.
[Middle English losen, from Old English losian, to perish, from los, loss; see leu- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. 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.