Greek poet, old boy deported by those who hate foreigners penning article (10)

'greek poet old boy deported by those who hate foreigners penning' is the definition.
The definition suggests a singular noun which matches the answer.

'article' is the wordplay.
I cannot quite understand how this works, but
'article' could be 'an' (English indefinite article) and 'an' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?