Longman Dictionary of Contemporary English - lost

~1 adj 1 »CANNOT BE FOUND« something that is lost is something you had but cannot now find; missing  (The lost file eventually turned up among Branson's papers.) 2 »CANNOT FIND YOUR WAY« unable to find your way or not knowing where you are  (Police are generally happy to give directions to lost tourists. | get lost (=become lost))  (I got thoroughly lost on the way here.) 3 »WASTED« only before noun not used properly; wasted  (It'll be impossible to make up the lost time. | lost opportunities/chances etc)  (lost market opportunities) 4 feel/be lost (in the crowd) to not feel confident about what to do or how to behave, especially among people you do not know  (Will your child feel lost at a nursery?) 5 Get lost! spoken used to tell someone rudely to go away 6 »IN THOUGHT ETC« thinking so hard about something or being so interested in something that you do not notice what is happening around you + in  (I was lost in the beauty of the scenery.) lost in thought  (Poirot remained lost in thought. | lost to the world)  (Alex sat reading, lost to the world.) 7 get lost (in sth) to be forgotten or not noticed in a complicated process or busy time  (It's easy for your main points to get lost in a long speech.) 8 »NOT UNDERSTAND« be lost to be completely confused by a complicated explanation  ("Did you understand the instructions?" "No, I'm totally lost.") 9 be lost on sb if something is lost on someone, they do not understand or want to accept it  (All my warnings were completely lost on Beth.) 10 be lost for words to be unable to say anything because you are very surprised, upset etc  (It's not often Glenda's lost for words.) 11 »NOT EXISTING« not existing or owned any more  (the lost dreams of her youth) 12 »DESTROYED/KILLED« destroyed, ruined, or killed  (lost at sea/lost in battle etc)  (The whole crew was lost at sea.) 13 a lost cause something that has no chance of succeeding  (Trying to interest my son in classical music is a lost cause.) 14 lost soul often humorous someone who does not seem know where they are or what to do  (- see also give sb up for dead/lost etc give1, make up for lost time make1, there is no love lost between love2 (11)) ~2 the past tense and past participle of lose