Gloomy song for one free to return (5)
I believe the answer is:
dirge
'gloomy song' is the definition.
'dirge' can be an answer for 'song' (dirge is a kind of song). I am not sure about the 'gloomy' bit.
'for one free to return' is the wordplay.
'for one' becomes 'eg' (both can mean 'for example').
'free' becomes 'rid' (to be free of something is to be rid of it).
'to return' is a reversal indicator.
'eg'+'rid'='egrid'
'egrid' back-to-front is 'DIRGE'.
Can you help me to learn more?
(Other definitions for dirge that I've seen before include "A depressing number" , "part of funeral, perhaps" , "Dragging piece" , "Funeral song" , "Keen; lament" .)