A dialectal or archaic term, possibly referring to a crowd or a group of people, or alternatively a disease in poultry; meanings vary by region.
Of uncertain origin; possibly related to crowd or to Scottish/Northern English dialect words; the ornithological sense may be unrelated.
Crood is one of those words that reminds us how many truly obsolete or hyper-regional words exist in English's history—it's hard to even pin down what it meant because it was so localized.
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