No room for Crazy Horse (3)
I believe the answer is:
bay
This could be a double definition.
'no room' is the first definition.
'bay' can be an answer for 'room' (bay is a kind of room). I am unsure of the 'no' bit.
'crazy horse' is the second definition.
'bay' can be an answer for 'horse' (bay is a kind of horse). I'm unsure of the 'crazy' bit.
'for' is the link.
(Other definitions for bay that I've seen before include "Botany or Biscay, for example" , "Sea inlet" , "Parking slot" , "Chestnut" , "Inlet, cove" .)