Suspender beat blouse? (6,3)

I believe the answer is:

halter top

I'm a little stuck... Click here to teach me more about this clue!

'suspender' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'beat blouse?' is the wordplay.
'beat' becomes 'halter' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'blouse?' becomes 'top' (blouse is a kind of top).
'halter'+'top'='HALTER TOP'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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