Loafer relied on working without energy (5)
I believe the answer is:
idler
'loafer' is the definition.
(I know that loafer can be written as idler)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for idler that I've seen before include "Man off watch" , "Sluggard" , "One reluctant to work" , "Long doleful cry" , "Drone" .)