Stay forward (4)
I believe the answer is:
prop
I believe this clue is a double definition.
'stay' is the first definition.
(I've seen this before)
'forward' is the second definition.
(I've seen this before)
(Other definitions for prop that I've seen before include "Support (a rugby player?)" , "Support; rugby forward" , "player involved in scrum" , "one playing Rugby" , "Moveable object used on stage" .)