Steady couple (5)
I believe the answer is:
brace
I believe this clue is a double definition.
'steady' is the first definition.
('brace' can be a synonym of 'steady')
'couple' is the second definition.
('brace' can be a synonym of 'couple')
(Other definitions for brace that I've seen before include "Strengthen; pair" , "Two of a kind" , "Pair - supporting beam" , "hand tool" , "Pair of game-birds" .)