sustainer (n.)

• abettor
• admirer
• advocate
• aficionado
• alpenstock
• angel
• apologist
• arm
• back
• backbone
• backer
• backing
• bandeau
• bearer
• bra
• brace
• bracer
• bracket
• brassiere
• broadcast
• buff
• buttress
• cane
• carrier
• cervix
• champion
• commercial
• corset
• crook
• crutch
• defender
• dependence
• endorser
• exponent
• fan
• fulcrum
• girdle
• guy
• jock
• jockstrap
• lover
• mainstay
• maintainer
• mast
• neck
• newscast
• partisan
• patron
• promoter
• prop
• protagonist
• rebroadcast
• reinforcement
• reinforcer
• reliance
• rerun
• rest
• rigging
• second
• seconder
• sectary
• serial
• shoulder
• shroud
• sider
• spine
• sponsor
• sportscast
• sprit
• staff
• stalwart
• standby
• stave
• stay
• stick
• stiffener
• strengthener
• support
• supporter
• sympathizer
• upholder
• votary
• well-wisher