Opposition second in table above Reading (8)
I believe the answer is:
aversion
'opposition' is the definition.
(thesaurus)
'second in table above reading' is the wordplay.
'second in table' becomes 'a' (2nd letter of 'table').
'above' is a charade indicator (letters next to each other) (in a down clue, some letters go above others).
'reading' becomes 'version' (a reading can be an interpretation or version).
'a'+'version'='AVERSION'
(Other definitions for aversion that I've seen before include "Dislike, hatred" , "phobia" , "A strong dislike or repugnance" , "Disgust" , "serious dislike" .)