no longer possessed or retained

lost friends.

no longer to be found

lost articles.

having gone astray or missed the way; bewildered as to place, direction, etc.

lost children.

not used to good purpose, as opportunities, time, or labor; wasted

a lost advantage.

being something that someone has failed to win

a lost prize.

ending in or attended with defeat

a lost battle.

destroyed or ruined

lost ships.

preoccupied; rapt

He seems lost in thought.

distracted; distraught; desperate; hopeless

the lost look of a man trapped and afraid.

pt. and pp. of lose. ?

get lost

Slang .

to absent oneself

I think I'll get lost before an argument starts.

to stop being a nuisance

If they call again, tell them to get lost.

lost to

no longer belonging to.

no longer possible or open to

The opportunity was lost to him.

insensible to

lost to all sense of duty.