1. [v]  be set at a disadvantage; "This author really suffers in translation"
2. [v]  fail to win; "We lost the battle but we won the war"
3. [v]  retreat
4. [v]  place (something) where one cannot find it again; "I misplaced my eyeglasses"
5. [v]  suffer the loss of a person through death or removal; "She lost her husband in the war"; "The couple that wanted to adopt the child lost her when the biological parents claimed her"
6. [v]  fail to perceive or to catch with the senses or the mind; "I missed that remark"; "She missed his point"; "We lost part of what he said"
7. [v]  allow to go out of sight; "The detective lost the man he was shadowing after he had to stop at a red light"
8. [v]  miss from one's possessions; lose sight of; "I've lost my glasses again!"
9. [v]  fail to keep or to maintain; cease to have, either physically or in an abstract sense; "She lost her purse when she left it unattended on her seat"
10. [v]  fail to get or obtain; "I lost the opportunity to spend a year abroad"
11. [v]  fail to make money in a business; make a loss or fail to profit; "I lost thousands of dollars on that bad investment!"; "The company turned a loss after the first year"

1. \Lose\, v. t. [imp. & p. p. {Losing}.] [OE. losien to
   loose, be lost, lose, AS. losian to become loose; akin to OE.
   leosen to lose, p. p. loren, lorn, AS. le['o]san, p. p. loren
   (in comp.), D. verliezen, G. verlieren, Dan. forlise, Sw.
   f["o]rlisa, f["o]rlora, Goth. fraliusan, also to E. loose, a
   & v., L. luere to loose, Gr. ?, Skr. l? to cut. [root]127.
   Cf. {Analysis}, {Palsy}, {Solve}, {Forlorn}, {Leasing},
   {Loose}, {Loss}.]
   1. To part with unintentionally or unwillingly, as by
      accident, misfortune, negligence, penalty, forfeit, etc.;
      to be deprived of; as, to lose money from one's purse or
      pocket, or in business or gaming; to lose an arm or a leg
      by amputation; to lose men in battle.
            Fair Venus wept the sad disaster Of having lost her
            favorite dove.                        --Prior.
   2. To cease to have; to possess no longer; to suffer
      diminution of; as, to lose one's relish for anything; to
      lose one's health.
            If the salt hath lost his savor, wherewith shall it
            be salted ?                           --Matt. v. 13.
   3. Not to employ; to employ ineffectually; to throw away; to
      waste; to squander; as, to lose a day; to lose the
      benefits of instruction.
            The unhappy have but hours, and these they lose.
                                                  --Dryden.
   4. To wander from; to miss, so as not to be able to and; to
      go astray from; as, to lose one's way.
            He hath lost his fellows.             --Shak
   5. To ruin; to destroy; as destroy; as, the ship was lost on
      the ledge.
            The woman that deliberates is lost.   --Addison.
   6. To be deprived of the view of; to cease to see or know the
      whereabouts of; as, he lost his companion in the crowd.
            Like following life thro' creatures you dissect, You
            lose it in the moment you detect.     --Pope.
   7. To fail to obtain or enjoy; to fail to gain or win; hence,
      to fail to catch with the mind or senses; to miss; as, I
      lost a part of what he said.
            He shall in no wise lose his reward.  --Matt. x. 42.
            I fought the battle bravely which I lost, And lost
            it but to Macedonians.                --Dryden.
   8. To cause to part with; to deprive of. [R.]
            How should you go about to lose him a wife he loves
            with so much passion ?                --Sir W.
                                                  Temple.
   9. To prevent from gaining or obtaining.
            O false heart ! thou hadst almost betrayed me to
            eternal flames, and lost me this glory. --Baxter.
   {To lose ground}, to fall behind; to suffer gradual loss or
      disadvantage.
   {To lose heart}, to lose courage; to become timid. ``The
      mutineers lost heart.'' --Macaulay.
   {To lose one's head}, to be thrown off one's balance; to lose
      the use of one's good sense or judgment.
            In the excitement of such a discovery, many scholars
            lost their heads.                     --Whitney.
   {To lose one's self}.
      (a) To forget or mistake the bearing of surrounding
          objects; as, to lose one's self in a great city.
      (b) To have the perceptive and rational power temporarily
          suspended; as, we lose ourselves in sleep.
   {To lose sight of}.
      (a) To cease to see; as, to lose sight of the land.
      (b) To overlook; to forget; to fail to perceive; as, he
          lost sight of the issue.
   

2. \Lose\, v. i.
   To suffer loss, disadvantage, or defeat; to be worse off,
   esp. as the result of any kind of contest.
         We 'll . . . hear poor rogues Talk of court news; and
         we'll talk with them too, Who loses and who wins; who's
         in, who's out.                           --Shak.
   

(MIT) 1. To fail. A program loses when it encounters an exceptional condition or fails to work in the expected manner.

2. To be exceptionally unesthetic or crocky.

3. Of people, to be obnoxious or unusually stupid (as opposed to ignorant).

4. Refers to something that is losing, especially in the phrases "That's a lose!" and "What a lose!"

[Jargon File]