Waiting in readiness (2,3)
I believe the answer is:
on ice
'waiting in readiness' is the definition.
(on ice means ready or prepared)
This is all the clue.
(Other definitions for on ice that I've seen before include "Awaiting decision" , "Where one might find slippers" , "Kept in readiness" , "kept for later" , "not to be furthered?" .)