Crusty drone? (6)
I believe the answer is:
loafer
'drone?' is the definition.
(drone is a kind of loafer)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for loafer that I've seen before include "Comfortable shoe or a do-nothing" , "one taking it easy" , "One habitually putting feet up" , "One shirking work" , "Casual footwear" .)