Article penned by mature editor is greatly praised (8)
I believe the answer is:
adulated
'greatly praised' is the definition.
'adulated' can be an answer for 'praised' (I've seen this before). I am unsure of the 'greatly' bit.
'article penned by mature editor' is the wordplay.
'article' becomes 'a' (English indefinite article).
'penned by' is an insertion indicator (inserted letters are penned in).
'mature' becomes 'adult' (similar in meaning).
'editor' becomes 'ed' (abbreviation).
'a' inserted inside 'adult' is 'adulat'.
'adulat'+'ed'='ADULATED'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for adulated that I've seen before include "Flattered in an obsequious manner" , "given excessive praise perhaps" , "Praised" .)