In"u*lin (?), n. [From NL. Inula Helenium, the elecampane: cf. F. inuline.] (Chem.) A substance of very wide occurrence. It is found dissolved in the sap of the roots and rhizomes of many composite and other plants, as Inula, Helianthus, Campanula, etc., and is extracted by solution as a tasteless, white, semicrystalline substance, resembling starch, with which it is isomeric. It is intermediate in nature between starch and sugar. Called also dahlin, helenin, alantin, etc.