say it: LOO-zur
loser is a noun meaning "a contestant who loses the contest". It carries 3 recorded senses.
a contestant who loses the contest
a person with a record of failing; someone who loses consistently
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for loser come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.