1.  protagonist(n = noun.person) admirer, booster, champion, friend, supporter - a person who backs a politician or a team etc.; "all their supporters came out for the game"; "they are friends of the library"
is a kind of advocate, advocator, exponent, proponent
has particulars: anglophil, anglophile, believer, truster, boswell, cheerleader, confederate, corporatist, enthusiast, partisan, partizan, francophil, francophile, free trader, functionalist, jacobite, loyalist, stalwart, new dealer, graecophile, philhellene, philhellenist, mainstay, pillar, roundhead, seconder, shavian, endorser, indorser, ratifier, subscriber, sympathiser, sympathizer, well-wisher, toaster, wassailer, maintainer, sustainer, upholder, verifier, voucher, whig

2.  protagonist(n = noun.person) agonist - the principal character in a work of fiction;
is a kind of character, fictional character, fictitious character
has particulars: antihero

   One who takes the leading part in a drama; hence, one who takes lead in some great scene, enterprise, conflict, or the like. [1913 Webster]
"Shakespeare, the protagonist on the great of modern poetry." [1913 Webster]

protagonist, n.
1 the chief person in a drama, story, etc.
2 the leading person in a contest etc.; a principal performer.
3 (usu. foll. by of, for) disp. an advocate or champion of a cause, course of action, etc. (a protagonist of women's rights).

Etymology:
Gk protagonistes (as PROTO-, agonistes actor)

N  the drama, the stage, the theater, the play, film the film, movies, motion pictures, cinema, cinematography, theatricals, dramaturgy, histrionic art, buskin, sock, cothurnus, Melpomene and Thalia, Thespis, play, drama, stage play, piece, five-act play, tragedy, comedy, opera, vaudeville, comedietta, lever de rideau, interlude, afterpiece, exode, farce, divertissement, extravaganza, burletta, harlequinade, pantomime, burlesque, opera bouffe, ballet, spectacle, masque, drame comedie drame, melodrama, melodrame, comidie larmoyante, sensation drama, tragicomedy, farcical-comedy, monodrame monologue, duologue trilogy, charade, proverbs, mystery, miracle play, musical, musical comedy, western, horse opera, flick, spy film, love story, adventure film, documentary, nature film, pornographic film, smoker, skin flick, X-rated film, act, scene, tableau, induction, introduction, prologue, epilogue, libretto, performance, representation, mise en scene, stagery, jeu de theatre, acting, gesture, impersonation, stage business, gag, buffoonery, light comedy, genteel comedy, low comedy, theater, playhouse, opera house, house, music hall, amphitheater, circus, hippodrome, theater in the round, puppet show, fantoccini, marionettes, Punch and Judy, auditory, auditorium, front of the house, stalls, boxes, pit, gallery, parquet, greenroom, coulisses, flat, drop, drop scene, wing, screen, side scene, transformation scene, curtain, act drop, proscenium, stage, scene, scenery, the boards, trap, mezzanine floor, flies, floats, footlights, offstage, orchestra, theatrical costume, theatrical properties, movie studio, back lot, on location, part, role, character, dramatis personae, repertoire, actor, thespian, player, method actor, stage player, strolling player, stager, performer, mime, mimer, artists, comedian, tragedian, tragedienne, Roscius, star, movie star, star of stage and screen, superstar, idol, sex symbol, supporting actor, supporting cast, ham, hamfatter, masker, pantomimist, clown harlequin, buffo, buffoon, farceur, grimacer, pantaloon, columbine, punchinello, pulcinello, pulcinella, extra, bit- player, walk-on role, cameo appearance, mute, figurante, general utility, super, supernumerary, company, first tragedian, prima donna, protagonist, jeune premier, debutant, debutante, light comedian, genteel comedian, low comedian, walking gentleman, amoroso, heavy father, ingenue, jeune veuve, mummer, guiser, guisard, gysart, masque, mountebank, Jack Pudding, tumbler, posture master, acrobat, contortionist, ballet dancer, ballet girl, chorus singer, coryphee danseuse, property man, costumier, machinist, prompter, call boy, manager, director, stage manager, acting manager, producer, entrepreneur, impresario, backer, investor, angel, dramatic author, dramatic writer, play writer, playwright, dramatist, mimographer, dramatic, theatric, theatrical, scenic, histrionic, comic, tragic, buskined, farcical, tragicomic, melodramatic, operatic, stagy, on the stage, on the boards, on film, before the floats, before an audience, behind the scenes, fere totus mundus exercet histrionem, suit the action to the word, the word to the action, the play's the thing, to wake the soul by tender strokes of art.

N  proficient, expert, adept, dab, dabster, crackerjack, connoisseur, master, master hand, prima donna, first fiddle, top gun, chef de cuisine, top sawyer, protagonist, past master, mahatma, picked man, medallist, prizeman, veteran, old stager, old campaigner, old soldier, old file, old hand, man of business, man of the world, nice hand, good hand, clean hand, practiced hand, experienced eye, experienced hand, marksman, good shot, dead shot, crack shot, ropedancer, funambulist, acrobat, cunning man, conjuror, wizard, genius, mastermind, master head, master spirit, cunning blade, sharp blade, sharp fellow, jobber, cracksman, politician, tactician, strategist, pantologist, admirable Crichton, Jack of all trades, prodigy of learning.