Populin \Pop"u*lin\, n. [L. populus poplar: cf. F. populine.] (Chem.) A glycoside, related to salicin, found in the bark of certain species of the poplar ({Populus}), and extracted as a sweet white crystalline substance.
Populus n : a genus of trees of the family Salicaceae that is found in the northern hemisphere; poplars [syn: {genus Populus}]