Hoods a hundred birds (5)

I believe the answer is:

cowls

'hoods' is the definition.
('cowl' can be a synonym of 'hood')

'a hundred birds' is the wordplay.
'a hundred' becomes 'c' (Roman numeral).
'birds' becomes 'owls' (owl is a kind of bird).
'c'+'owls'='COWLS'

(Other definitions for cowls that I've seen before include "Coverings" , "Monks' hoods" .)

I've seen this clue in the Sydney Morning Herald.

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