plumulaceous,a.|pluːmjuːˈleɪʃəs| [f. L. plūmula(seeprec.) + -aceous.] Of the nature of or resembling a plumule, downy. 1879in Webster Suppl.1890Coues Gen.Ornith. 139 The ventral feathers are usually more largely plumulaceous, and less flat and imbricated.