Remain for support (4)
I believe the answer is:
stay
This clue is a double definition.
'remain' is the first definition.
(synonyms)
'support' is the second definition.
(stay is a kind of support)
'for' acts as a link.
(Other definitions for stay that I've seen before include "Thin strip used to stiffen a garment" , "Don't go!" , "Rope to brace an upright" , "Stop; support" , "control" .)