1.InterjectionUsed to rudely tell somebody to go away or leave one alone.
2.VerbTo lose one's way.
"Don't you have a map? How did we get lost?; I got lost in his reasoning."
3.VerbTo go missing; to be in a location unknown to someone who is looking for it.
"My keys got lost while I was out today."
4.VerbTo be absent, to seem to be absent.
"The violins get lost with the rest of the music."
5.VerbTo exit from the scene.
"I don't want to have to tell you again: Get lost!; They had a row and Fred told Jack to get lost.; Jack did a good job of getting lost: nobody saw him for 4 years."