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

Dionysus Maecenas Samaritan Santa Claus 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