Formal “about turn” in a flawed trial (6)
I believe the answer is:
ritual
'formal' is the definition.
(thesaurus)
'turn in a flawed trial' is the wordplay.
'turn' becomes 'u' (a 'U-turn' is a kind of turn).
'in' indicates putting letters inside.
'a flawed' is an anagram indicator (I've seen this in other clues).
'trial' is an anagram of 'rital'.
'u' put inside 'rital' is 'RITUAL'.
'about' is the link.
(Other definitions for ritual that I've seen before include "Habits" , "Ceremony, solemn procedure" , "Prescribed ceremonial procedure" , "Ceremony following a prescribed order" , "Actions performed as in a religious ceremony" .)