Definition of bitterroot

• n. - A plant (Lewisia rediviva) allied to the purslane, but with fleshy, farinaceous roots, growing in the mountains of Idaho, Montana, etc. It gives the name to the Bitter Root mountains and river. The Indians call both the plant and the river Spaet'lum.
• n. - A plant (Lewisia rediviva) allied to the purslane, but with fleshy, farinaceous roots, growing in the mountains of Idaho, Montana, etc. It gives the name to the Bitter Root mountains and river. The Indians call both the plant and the river Spaet'lum.