Something said about an evangelist (6)
I believe the answer is:
remark
'something said' is the definition.
(a comment or utterance)
'about an evangelist' is the wordplay.
'about' becomes 're' (regarding).
'an evangelist' becomes 'Mark' (St Mark).
're'+'mark'='REMARK'
(Other definitions for remark that I've seen before include "Something said; take notice of" , "Mention - observe" , "Notice; happen to say" , "Say as a comment" , "Written or spoken comment" .)