Grooms have space (4)
I believe the answer is:
room
'space' is the definition.
(enough space or room to do something)
'grooms have' is the wordplay.
'have' says the answer is hidden in the clue.
'ROOM' is hidden in the letters of 'grooms'.
(Other definitions for room that I've seen before include "Enclosed space in a building" , "Adequate space" , "Space, area" , "bedsit?" , "See 17" .)