Hesitate to declare after Warwickshire's opening (5)
I believe the answer is:
waver
'hesitate' is the definition.
('waver' can be a synonym of 'hesitate')
'declare after warwickshire's opening' is the wordplay.
'declare' becomes 'aver' (averring is a kind of declaring).
'after' is a charade indicator (letters next to each other).
'opening' says to take the initial letters.
The initial letter of 'warwickshire' is 'w'.
'aver' put after 'w' is 'WAVER'.
'to' acts as a link.
(Other definitions for waver that I've seen before include "hold back" , "Be irresolute; flicker" , "Begin to weaken" , "Be uncertain about decision" , "Vacillate" .)