One Northern European eclipsed by poet is amateur (10)
I believe the answer is:
dilettante
'is amateur' is the definition.
(I've seen this before)
'one northern european eclipsed by poet' is the wordplay.
'one' becomes 'i' (Roman numeral).
'northern european' becomes 'lett' (I've seen this in another clue).
'eclipsed by' is an insertion indicator.
'poet' becomes 'Dante' (ltth- and ltth-century Italian poet).
'i'+'lett'='ilett'
'ilett' placed inside 'dante' is 'DILETTANTE'.
(Other definitions for dilettante that I've seen before include "amateur artist" , "One dabbling" , "Amateurish" , "Superficial dabbler in the arts - title at end (anag)" , "Arty type" .)