a person, team, nation, etc., that loses

The visiting team was the loser in the series.

Informal .

a person who has been convicted of a misdemeanor or, esp., a felony

a two-time loser.

a person who has failed at a particular activity

a loser at marriage.

someone or something that is marked by consistently or thoroughly bad quality, performance, etc.

Don't bother to see that film, it's a real loser.

Slang . a misfit, esp. someone who has never or seldom been successful at a job, personal relationship, etc.

noun

achiever , success , winner

noun

also-ran * , deadbeat * , defeated , disadvantaged , down-and-outer , dud * , failure , flop * , flunkee , has-been , underdog , underprivileged , bust , fiasco , washout , miserable , wretch , also-ran , also ran , bomb , deadbeat , flop , lemon , nerd , schlemiel