say it: proh-TAG-uh-nuhst
protagonist is a noun meaning "a person who backs a politician or a team etc.". It carries 2 recorded senses.
the principal character in a work of fiction
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 protagonist 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.