Support for a proposal? (4)
I believe the answer is:
knee
'support for a proposal?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for knee that I've seen before include "Genuflector?" , "It jerks reactively" , "proposal might be made on one" , "Wounded in Indian Wars action" , "Leg hinge" .)