Quick to declare (7)
I believe the answer is:
express
This clue is a double definition.
'quick' is the first definition.
(I've seen this before)
'declare' is the second definition.
(I know that declare is a more specific form of the action say)
'to' acts as a link.
(Other definitions for express that I've seen before include "Utter; speedy" , "Convey in words; train" , "Verbalise - very fast" , "Train; utter" , "Squeeze out - quick" .)