Spooner’s to miss party, leading to unpleasant response (8)
I believe the answer is:
backlash
'response' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for backlash that I've seen before include "Violent reaction to an event - using whip?" , "Sudden violent reaction to an action or situation" , "Strong negative reaction to a development" , "Provoked adverse reaction" , "Hostile reaction" .)