defender (n.)

• abettor
• admirer
• advocate
• aficionado
• angel
• apologist
• backer
• buff
• champion
• dependence
• endorser
• exponent
• fan
• guard
• justifier
• lover
• mainstay
• maintainer
• paladin
• partisan
• patron
• patroness
• pillar
• pleader
• promoter
• proponent
• protagonist
• protector
• reliance
• rock
• second
• seconder
• sectary
• sider
• sponsor
• stalwart
• standby
• support
• supporter
• sustainer
• sympathizer
• tower
• upholder
• vindicator
• votary
• well-wisher