Coached in art form by journalist (7)
I believe the answer is:
trained
'coached' is the definition.
('train' can be a synonym of 'coach')
'in art form by journalist' is the wordplay.
'form' is an anagram indicator (a different form of the same letters).
'by' says to put letters next to each other.
'journalist' becomes 'ed' (short for editor).
'art' anagrammed gives 'tra'.
'in' after 'tra' is 'train'.
'train'+'ed'='TRAINED'
(Other definitions for trained that I've seen before include "Taught; exercised" , "Did exercises" , "Coached" , "Instructed - took aim" , "Schooled" .)