Projectile containing nut? (5)
I believe the answer is:
shell
This could be a double definition.
'projectile' is the first definition.
(I have seen 'Explosive projectile' mean 'shell' so perhaps 'projectile' could also mean 'shell')
'nut?' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'containing' acts as a link.
Can you help me to learn more?
(Other definitions for shell that I've seen before include "multinational?" , "Hard casing; a racing boat" , "attack with bombs" , "Explosive projectile" , "Conch, perhaps" .)