Firm stumped by unheaded dispatch (7)
I believe the answer is:
staunch
'firm' is the definition.
(I've seen this before)
'stumped by unheaded dispatch' is the wordplay.
I cannot quite understand how this works, but
'stumped' could be 'st' (cricket abbreviation) and 'st' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for staunch that I've seen before include "Check" , "Faithful and true" , "solid" , "Stop bleeding; trusty" , "Dependable; stop (flow)" .)