Crossword Genius

Poor bird's innards bad at intervals (2,5,3,5)

Ross

I believe the answer is:

in dribs and drabs

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'intervals' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'poor bird's innards bad' is the wordplay.
'poor' indicates anagramming the letters.
'birds'+'innards'+'bad'='birdsinnardsbad'
'birdsinnardsbad' with letters rearranged gives 'IN DRIBS AND DRABS'.

'at' is the link.

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I've seen this clue in The Guardian.
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