/nil"guy/ , n. , pl. nilgais , ( esp. collectively ) nilgai .
a large, Indian antelope, Boselaphus tragocamelus, the male of which is bluish gray with small horns, the female tawny and hornless.
Also, nylghai, nylghau . Also called blue bull .
[ 1880-85; nilgay lit., blue cow ]