Explosive 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 an association between them I don't understand?
'explosive found' is the wordplay.
I cannot quite understand how this works, but
'explosive' could be 'he' (abbreviation for high explosive) and 'he' is found in 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 "Mortar missile" , "Crustacean's protection" , "Mollusc's protection" , "ammunition" , "Hard protective case" .)