Beneath loose pants, grip is inferior (14)

I believe the answer is:

understrapping

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'is inferior' is the definition.
I can't tell whether this definition defines the answer.

'beneath loose pants grip' is the wordplay.
'beneath' becomes 'under' (under means beneath or underneath).
'loose' indicates anagramming the letters (letters are loosened from their original positions).
'pants'+'grip'='pantsgrip'
'pantsgrip' anagrammed gives 'strapping'.
'under'+'strapping'='UNDERSTRAPPING'

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I've seen this clue in The Guardian.

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