to lose

To lose is to no longer have something you once had.

You can lose possessions, lose money, lose a job.

You lose a game or contest by failing to win.

To lose someone is to be separated from them—through death, departure, or simply losing track of them in a crowd.

I lost my keys.

She lost her father last year.

Don't lose sight of what matters.

To lose yourself in something is to become absorbed: He lost himself in the music.

The opposite of lose is find, win, or keep, depending on context.