Firework in crate (6)
I believe the answer is:
banger
This could be a double definition.
'firework' is the first definition.
(banger is a kind of firework)
'crate' is the second definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'in' is the link.
Can you help me to learn more?
(Other definitions for banger that I've seen before include "Slangily, a noisy old car or a sausage" , "Old rattling car or slang sausage" , "Clapped-out car" , "set off on November 5" , "Sausage (informal)" .)