-_nə̇st noun
( -s )
Etymology: Greek prōtagōnistēs, from prōt-, prot- + agōnistēs competitor at games, debater, actor, from agōnizesthai to compete for a prize, contend, from agōn gathering, assembly at games, contest — more at agony
1.
a. : one who takes the leading part in a drama — opposed to antagonist
b. : the chief character of a novel or story in or around whom the action centers
2.
a. : the spokesman or leader for a cause : the principal mover : champion
was not only the protagonist of his age; he was the symbol of all its inner meaning — W.O.Douglas
b. : an active participant : the supporter of an idea or action : advocate
there remains a problem of market power that the protagonists of big business … have not understood — E.S.Mason
3. : a muscle that by its contraction actually causes a particular movement