Low rubbish describing heavy fellow's chest (5)

I believe the answer is:

moobs

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'heavy fellow's chest' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'low rubbish' is the wordplay.
'low' becomes 'moo' (both can mean to make a cow noise).
'rubbish' becomes 'bs' (I am not sure about this - if you are sure you should believe this answer much more).
'moo'+'bs'='MOOBS'

'describing' is the link.

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I've seen this clue in The Guardian.

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