downy poplar dow·ny·pop·lar uncommon noun 1. North American poplar with large rounded scalloped leaves and brownish bark and wood Synonymsswamp cottonwoodblack cottonwooddowny poplarswamp poplarPopulus heterophylla Related words Broader terms cottonwood WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
