Poem’s energy reflected in English crossword feature (7)
I believe the answer is:
eclogue
'poem's' is the definition.
(I've seen this before)
'energy reflected in english crossword feature' is the wordplay.
'energy' becomes 'go' (go can mean energy or enthusiasm).
'reflected' is a reversal indicator (letters reflected back).
'in' indicates putting letters inside.
'english' becomes 'E' (abbreviation).
'crossword feature' becomes 'clue' (I've seen this in another clue).
'go' reversed gives 'og'.
'e'+'clue'='eclue'
'og' placed within 'eclue' is 'ECLOGUE'.
(Other definitions for eclogue that I've seen before include "Lines written" , "Short pastoral poem" , "pastoral work" , "Bucolic" , "Poem about country" .)