Dislike test said to be involved (8)
I believe the answer is:
distaste
'dislike' is the definition.
(I know that distaste is a type of dislike)
'test said to be involved' is the wordplay.
'to be involved' indicates anagramming the letters (involved can mean confusing or complex).
'test'+'said'='testsaid'
'testsaid' is an anagram of 'DISTASTE'.
(Other definitions for distaste that I've seen before include "Adverse reaction" , "Is stated (anag.)" , "Abhorrence" , "lack of relish?" , "Dislike of something unsavoury" .)