Ancient poet edges away from punk describing American's sporting achievement (7)
I believe the answer is:
homerun
'american's sporting achievement' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'ancient poet edges away from punk' is the wordplay.
'ancient poet' becomes 'homer' (Homer is an example. I am not sure about the 'ancient' bit.).
'edges away from' says to take the centre.
The centre of 'punk' is 'un'.
'homer'+'un'='HOMERUN'
'describing' acts as a link.
Can you help me to learn more?
(Another definition for homerun that I've seen is " big hit in America".)