What shows middle is plump, having trim clothing? (4,3)

I believe the answer is:

crop top

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'what shows middle is plump' is the definition.
I know nothing about this answer so I cannot tell whether this works.

'trim clothing?' is the wordplay.
'trim' becomes 'crop' (synonyms).
'clothing?' becomes 'top' (top is a kind of clothing).
'crop'+'top'='CROP TOP'

'having' acts as a link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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