Sad daughter carrying books did cry (7)

I believe the answer is:

blubbed

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'did cry' is the definition.
Both the answer and definition are past participle verbs.
Perhaps you can see an association between them that I can't see?

'sad daughter carrying books' is the wordplay.
'sad' becomes 'blue' (similar in meaning).
'daughter' becomes 'd' (genealogical abbreviation).
'carrying' is an insertion indicator.
'books' becomes 'BB' (an abbreviation for book written twice).
'blue'+'d'='blued'
'blued' placed around 'bb' is 'BLUBBED'.

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I've seen this clue in The Guardian.

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