lost
adjective
lɒst 
lɔːst lɑːst 
1 unable to find your way; not knowing where you areWe always get lost in London.We're completely lost.2 that cannot be found or brought backI'm still looking for that lost file.Your cheque must have got lost in the post.3 [usually before noun] that cannot be obtained; that cannot be found or created againThe strike cost them thousands of pounds in lost business.She's trying to recapture her lost youth.He regretted the lost (= wasted) opportunity to apologize to her.the lost art of letter-writing4 [not before noun] unable to deal successfully with a particular situationWe would be lost without your help.I felt so lost after my mother died.He's a lost soul (= a person who does not seem to know what to do, and seems unhappy).5 [not before noun] unable to understand something because it is too complicatedThey spoke so quickly I just got lost.Hang on a minute—I'm lost. see also lose verbIdioms
all is not lost
there is still some hope of making a bad situation better
All is not lost—we still haven't tried the banks for a loan.be lost for words
to be so surprised, confused, etc. that you do not know what to say
be lost in something
to be giving all your attention to something so that you do not notice what is happening around you
to be lost in thoughtbe lost on somebody
to be not understood or noticed by somebody
His jokes were completely lost on most of the students.be lost to the world
to be giving all your attention to something so that you do not notice what is happening around you
When he's listening to music he's lost to the world.get lost
(informal) a rude way of telling somebody to go away, or of refusing somethingTell him to get lost.‘Lend us the car, won't you?’ ‘Get lost!’give somebody up for lost
(formal) to stop expecting to find somebody alivemake up for lost time
to do something quickly or very often because you wish you had started doing it sooner
I'll have to work hard now to make up for lost time.