Vessel involved in a storm (6)

I believe the answer is:

teacup

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'vessel' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for teacup that I've seen before include "China possibly" , "Earl Grey holder?" , "proverbially stormy location" , "leaves on one's bottom?" , "Drinking vessel" .)

I've seen this clue in the Evening Standard.

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