Knowledgeable English press chief pocketing old gold coin (8)
I believe the answer is:
educated
'knowledgeable' is the definition.
(similar in meaning)
'english press chief pocketing old gold coin' is the wordplay.
'english' becomes 'e' (abbreviation).
'press chief' becomes 'ed' (editor).
'pocketing' means one lot of letters goes inside another.
'old gold coin' becomes 'ducat' (I've seen this in another clue).
'e'+'ed'='eed'
'eed' enclosing 'ducat' is 'EDUCATED'.
(Other definitions for educated that I've seen before include "Schooled, trained" , "Well-read" , "Learned - cultivated" , "Trained; learned" , "Clever" .)