Game with nine rooms (4)
I believe the answer is:
clue
'game with nine rooms' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for clue that I've seen before include "Hint towards solution" , "one of 28 here" , "It's here top be solved" , "contribution to crossword" , "Aid to puzzlers" .)