Crossword Genius

Could it cause an explosion around crustaceans? (5)

Ross

I believe the answer is:

shell

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This might be a double definition.

'could' is the first definition.
Although both the answer and definition are verbs in their base form, I don't understand how they can define each other.

'it cause an explosion around crustaceans?' is the second definition.
The definition suggests a singular noun which matches the answer.

Can you help me to learn more?

(Other definitions for shell that I've seen before include "Outer covering of 1 across, say" , "(Turtle's) carapace" , "Protective outer casing" , "Carapace or explosive missile" , "layer of jacket" .)

I've seen this clue in The Irish News.
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