Frank? He's not involved (6)
I believe the answer is:
honest
'frank?' is the definition.
('honest' can be similar in meaning to 'frank')
'he's not involved' is the wordplay.
'involved' indicates anagramming the letters (involved can mean confusing or complex).
'hes'+'not'='hesnot'
'hesnot' with letters rearranged gives 'HONEST'.
(Other definitions for honest that I've seen before include "Free of deceit, truthful by nature" , "Virtuous" , "Not cheating, just" , "Without dissimulation or guile" , "Trustworthy or candid" .)