Test said to produce antipathy (8)
I believe the answer is:
distaste
'antipathy' is the definition.
(I know that antipathy can be written as distaste)
'test said to produce' is the wordplay.
'to produce' is an anagram indicator.
'test'+'said'='testsaid'
'testsaid' with letters rearranged gives 'DISTASTE'.
(Other definitions for distaste that I've seen before include "Staidest (anag) - aversion (to)" , "Adverse reaction" , "Loathing" , "Negative feeling" , "Feeling of dislike or aversion" .)