Bellyache from drinking rum punch (5)

I believe the answer is:

grump

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'bellyache' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.

'from drinking rum punch' is the wordplay.
'from' indicates a hidden word.
'GRUMP' is hidden within 'drinking rum punch'.

Can you help me to learn more?

(Other definitions for grump that I've seen before include "grouse" , "pet?" , "Surly person" , "Sulky type" , "Sulky person" .)

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