Explosive device found on the beach (5)
I believe the answer is:
shell
'the beach' is the definition.
The definition and answer can be both natural objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'explosive device found' is the wordplay.
I cannot really see how this works, but
'explosive' could be 'he' (abbreviation for high explosive) and 'he' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'on' acts as a link.
Can you help me to learn more?
(Other definitions for shell that I've seen before include "Something used instead of money" , "Mortar missile" , "bomb?" , "Carapace or explosive missile" , "Characteristic feature of crustacean" .)