Backer

Noun

 * 1) One who, or that which, backs; especially one who backs a person or thing in a contest.

Adjective
backer

Thesaurus
abettor, acquaintance, admirer, advocate, aficionado, aid, aider, ally, almoner, almsgiver, alter ego, angel, apologist, assignor, assister, awarder, befriender, benefactor, benefactress, benefiter, best friend, bestower, bettor, bosom friend, brother, buff, casual acquaintance, champion, cheerful giver, close acquaintance, close friend, conferrer, confidant, confidante, consignor, contributor, defender, dependence, donator, donor, encourager, endorser, exponent, fairy godmother, familiar, fan, favorer, fellow, fellow creature, fellowman, feoffor, financer, friend, friend at court, funder, giver, good Samaritan, good person, grantor, grubstaker, guarantor, help, helper, helping hand, imparter, inseparable friend, intimate, investor, jack-at-a-pinch, lady bountiful, lover, mainstay, maintainer, meal ticket, ministering angel, ministrant, neighbor, other self, paranymph, partisan, patron, patroness, philanthropist, pickup, presenter, promoter, protagonist, punter, reliance, repository, second, seconder, sectary, settler, sider, sponsor, staker, stalwart, standby, subscriber, succorer, sugar daddy, support, supporter, surety, sustainer, sympathizer, testate, testator, testatrix, underwriter, upholder, votary, vouchsafer, well-wisher