Starts off every poem in collection in style of Homer (4)
I believe the answer is:
epic
'style of homer' is the definition.
(Homer was an epic poet)
'starts off every poem in collection' is the wordplay.
'starts off' indicates taking the first letters.
The initial letters of 'every poem in collection' is 'EPIC'.
'in' acts as a link.
(Other definitions for epic that I've seen before include "Long account" , "blockbuster" , "Impressive scope" , "(Of) immense (proportions)" , "Of heroic proportions" .)