Shrewdly arranged by an Irish poet, ultimately (8)
I believe the answer is:
astutely
'shrewdly' is the definition.
(synonyms)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for astutely that I've seen before include "cannily" , "Shrewdly" , "In a shrewd manner" .)