lose

For the verb: "to lose"

Simple Past:	lost
Past Participle:	lost

Concise Oxford English Dictionary © 2008 Oxford University Press:
lose /luːz/

▶verb (past and past part. lost)

• 1 be deprived of or cease to have or retain.

  ■ be deprived of (a relative or friend) through their death.

  ■ (of a pregnant woman) miscarry (a baby).

  ■ (be lost) be destroyed or killed.

  ■ decrease in (body weight).

  ■ (of a clock) become slow by (a specified amount of time).

  ■ (lose it) informal lose control of one's temper or emotions.

• 2 become unable to find.

  ■ (often lose one's (or the) way) become unable to follow (the right route).

  ■ evade or shake off (a pursuer).

  ■ N. Amer. informal get rid of.

  ■ (lose oneself in/be lost in) be or become deeply absorbed in.

• 3 fail to win (a game or contest).

• 4 earn less (money) than one is spending.

• 5 waste or fail to take advantage of: he may have lost his chance.

• 6 (lose out) be disadvantaged.

– phrases
lose face lose one's credibility.
lose heart become discouraged.
lose one's mind (or marbles) informal go insane.

– origin OE losian ‘perish, destroy’, also ‘become unable to find’, from los ‘loss’.

usage: Do not confuse lose and loose; lose is a verb meaning ‘no longer have’ or ‘become unable to find’ (I need to lose weight), while loose is normally an adjective, meaning ‘not firmly fixed in place or tied up’ (a loose tooth).