- Past tense and past participle of lose.
- Unable to find one's way: a lost child.
- No longer in the possession, care, or control of someone or something: a lost pen.
- No longer in existence; vanished or spent: lost youth.
- No longer known or practiced: a lost art.
- Beyond reach, communication, or influence: The expedition was lost to the world for two months.
- Not used to one's benefit or advantage: a lost opportunity.
- Having not been or unlikely to be won; unsuccessful: a lost battle; a lost cause.
- Beyond recovery or redemption; fallen or destroyed: a lost soul.
- Completely involved or absorbed; rapt: lost in thought.
- Bewildered or confused: I'm lost—can you start over?
- be lost on To have no effect or influence on: Her advice was lost on me.
- be lost on To be beyond the comprehension of: The lecture was lost on us.