lose / loōz/ • v. (past and past part. lost / lôst; läst/ ) [tr.] 1. be deprived of or cease to have or retain (something): I've lost my appetite Linda was very upset about losing her job | the company may find itself losing customers to cheaper rivals. ∎  cause (someone) to fail to gain or retain (something): you lost me my appointment at the university. ∎  be deprived of (a close relative or friend) through their death or as a result of the breaking off of a relationship: she lost her husband in the fire. ∎  (of a pregnant woman) miscarry (a baby) or suffer the death of (a baby) during childbirth. ∎  (be lost) be destroyed or killed, esp. through accident or as a result of military action: a fishing disaster in which 19 local men were lost. ∎  decrease in (body weight); undergo a reduction of (a specified amount of weight): she couldn't eat and began to lose weight. ∎  waste or fail to take advantage of (time or an opportunity): they lost every chance to score in the first inning he lost no time in attacking his opponent's tax proposals. ∎  (of a watch or clock) become slow by (a specified amount of time): this clock will neither gain nor lose a second. ∎  (lose it) inf. lose control of one's temper or emotions: in the end I completely lost it—I was screaming at them.2. become unable to find (something or someone): I've lost the car keys. ∎  cease or become unable to follow (the right route): the clouds came down, and we lost the path. ∎  evade or shake off (a pursuer): he came after me waving his revolver, but I easily lost him. ∎ inf. get rid of (an undesirable person or thing): lose that creep! ∎ inf. cause (someone) to be unable to follow an argument or explanation: sorry, Tim, you've lost me there. ∎  (lose oneself in/be lost in) be or become deeply absorbed in (something): he had been lost in thought.3. fail to win (a game or contest): the Bears lost the final game of the series | [intr.] they lost by one vote | [as adj.] (losing) the losing side. ∎  cause (someone) to fail to win (a game or contest): that shot lost him the championship.4. earn less (money) than one is spending or has spent: the paper is losing $500,000 a month | [intr.] he lost heavily on box-office flops. PHRASES: have nothing to lose be in a situation that is so bad that even if an action or undertaking is unsuccessful, it cannot make it any worse.lose face come to be less highly respected: he was trying to work out how he could go back home without losing face.lose heart become discouraged.lose one's heart tosee heart.lose height (of an aircraft) descend to a lower level in flight.lose one's mind (or one's marbles) inf. go insane.lose sleep worry about something: no one is losing any sleep over what he thinks of us.lose one's (or the) way become lost; fail to reach one's destination. ∎ fig. no longer have a clear idea of one's purpose or motivation in an activity or business: the company has lost its way and should pull out of general insurance.you can't lose used to express the conviction that someone must inevitably profit from an action or undertaking: we're offering them for only $5.00—you can't lose!PHRASAL VERBS: lose out be deprived of an opportunity to do or obtain something; be disadvantaged: youngsters who were losing out on regular schooling. ∎  be beaten in competition or replaced by: they were disappointed at losing out to Chicago in the playoffs.