Support is right behind (6)
I believe the answer is:
rafter
'support' is the definition.
(rafter is a kind of support)
'right behind' is the wordplay.
'right' becomes 'r' (common abbreviation).
'behind' becomes 'after' (eg after or behind someone in a queue).
'r'+'after'='RAFTER'
'is' is the link.
(Other definitions for rafter that I've seen before include "Sloping roof timber" , "traveller on log platform" , "person on floating logs" , "Roofing beam" , "Sloping beam that supports the roof" .)