(nautical, idiomatic) To die, to perish.

If one is not alert and attentive, one will not be successful.

One who wants everything may lose it all.

Alternative form of you win some, you lose some

(idiomatic) To achieve a portion of a goal, but fail to achieve the entire goal.

Third-person singular simple present indicative form of win the battle, but lose the war

To continue to wage war when it is clear that one is not going to win. / (idiomatic) To try to do something so difficult that it will probably end in failure.

present participle of lose one's cool

present participle of lose one's temper

present participle of lose one's mind