Additionally provides food to boy (5,2)

I believe the answer is:

tacks on

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

'food to boy' is the wordplay.
'food' becomes 'tack' (I've seen this before).
'to boy' becomes 'son' ('son' can be a synonym of 'boy').
'tack'+'son'='TACKS ON'

Can you help me to learn more?

(Another definition for tacks on that I've seen is " Fixes upon".)

I've seen this clue in The Telegraph.

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