Unexploded missiles found on the beach (6)
I believe the answer is:
shells
'unexploded missiles' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for shells that I've seen before include "Carapaces or military missiles" , "Carapaces or large missiles" , "Hard protective structures" , "Hard outer coatings or metal casings" , "Racing boats" .)