Bad pun initially causes extreme anger or disgust (10)
I believe the answer is:
repugnance
'disgust' is the definition.
(repugnance is a kind of disgust)
'bad pun initially causes extreme anger' is the wordplay.
'bad' indicates anagramming the letters.
'initially' says to take the initial letters.
The first letters of 'causes extreme' is 'ce'.
'pun'+'ce'+'anger'='punceanger'
'punceanger' is an anagram of 'REPUGNANCE'.
'or' is the link.
(Other definitions for repugnance that I've seen before include "Distaste" , "Intense disgust" , "Offended aversion" .)