Supporter

Noun

 * 1) Something that supports a structure such as a building.
 * 2) A person who supports, promotes, advocates or champions a cause or movement; an adherent.
 * 3)  An animal or figure that supports a shield in a coat of arms.
 * 4) A garter worn around the leg to support a sock or stocking

Synonyms

 * adherent
 * proponent

Antonyms

 * opponent
 * detractor

Thesaurus
abettor, acquaintance, adherent, admirer, advocate, aficionado, aid, almoner, almsgiver, alpenstock, alter ego, angel, apologist, appendage, arm, assignor, assistant, athletic supporter, attendant, awarder, back, backbone, backer, backing, bandeau, bearer, best friend, bestower, bosom friend, bra, brace, bracer, braces, bracket, brassiere, brother, buff, buttress, cane, carrier, casual acquaintance, cavaliere servente, cervix, champion, cheerful giver, close acquaintance, close friend, cohort, conferrer, confidant, confidante, consignor, contributor, corset, courtier, crook, crutch, dangler, defender, dependence, dependent, devotee, disciple, donator, donor, encourager, endorser, enthusiast, exponent, expounder, fairy godmother, familiar, fan, favorer, fellow, fellow creature, fellowman, feoffor, financer, flunky, follower, following, foundation garment, friend, friend at court, fulcrum, funder, galluses, girdle, giver, grantor, grubstaker, guard, guy, guywire, hanger, hanger-on, helper, henchman, homme de cour, imparter, inseparable friend, intimate, jock, jockstrap, lady bountiful, lover, mainstay, maintainer, mast, meal ticket, neck, neighbor, other self, pair of suspenders, paladin, paranymph, parasite, partisan, patron, patroness, philanthropist, pickup, presenter, promoter, prop, proponent, protagonist, protector, public, pursuer, pursuivant, reinforce, reinforcement, reinforcer, reliance, repository, rest, resting place, rigging, satellite, second, seconder, sectary, settler, shadow, shoulder, shroud, sider, spine, sponsor, sprit, staff, staker, stalwart, standby, standing rigging, stave, stay, stick, stiffener, stooge, strengthener, subscriber, successor, sugar daddy, support, suspender, suspenders, sustainer, sympathizer, tagtail, tail, testate, testator, testatrix, trainbearer, upholder, vindicator, votary, vouchsafer, walking stick, ward heeler, well-wisher