Not stunned, dispatching a single (5)
I believe the answer is:
unwed
'single' is the definition.
(synonyms)
'not stunned dispatching a' is the wordplay.
'not' becomes 'un' (I've seen this in other clues).
'stunned' becomes 'awed' (I've seen this in another clue).
'dispatching' indicates named letters should be taken away.
'awed' with 'a' taken out is 'wed'.
'un'+'wed'='UNWED'
(Other definitions for unwed that I've seen before include "Not married" , "Divorced" , "Single" , "Without benefit of clergy?" .)