los ‧ er /ˈluːzə $ -ər/ BrE AmE noun [countable]
[ Word Family: noun : ↑ loser , ↑ loss ; verb : ↑ lose ; adjective : ↑ lost ]
1 . someone who is in a worse situation than they were, because of something that has happened OPP winner :
If the strike continues, the people of Galway will be the real losers.
2 . someone who is never successful in life, work, or relationships:
What a loser!
The guy’s a born loser.
3 . someone who has lost a competition, game, election etc OPP winner
good/bad loser (=someone who behaves well or badly after losing)