Boxed, posh goods carried by sleigh (7)

I believe the answer is:

slugged

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'boxed' is the definition.
The answer and definition can be both to do with contact as well as being past participle verbs.
Maybe there's a link between them I don't understand?

'posh goods carried by sleigh' is the wordplay.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'goods' becomes 'gg' (an abbreviation for good written twice).
'carried by' is an insertion indicator.
'sleigh' becomes 'sled' (synonyms).
'u'+'gg'='ugg'
'ugg' inserted into 'sled' is 'SLUGGED'.

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(Another definition for slugged that I've seen is " Given heavy blow".)

I've seen this clue in The Independent.

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