Is throwing paint on book, terribly abused (7)

I believe the answer is:

bedaubs

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

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

'on book terribly abused' is the wordplay.
'on' means one lot of letters goes inside another (as in clothing 'on' a person).
'book' becomes 'b' (abbreviation for book).
'terribly' is an anagram indicator.
'abused' anagrammed gives 'bedaus'.
'b' going into 'bedaus' is 'BEDAUBS'.

Can you help me to learn more?

I've seen this clue in The Independent.

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