rhubarb Meaning, Definition & Usage

  1. noun long pinkish sour leafstalks usually eaten cooked and sweetened
    pieplant.
  2. noun plants having long green or reddish acidic leafstalks growing in basal clumps; stems (and only the stems) are edible when cooked; leaves are poisonous
    rhubarb plant.

WordNet

Rhu"barb noun
Etymology
F. rhubarbe, OF. rubarbe, rheubarbe, reubarbare, reobarbe, LL. rheubarbarum for rheum barbarum, Gr. (and ) rhubarb, from the river Rha (the Volga) on whose banks it grew. Originally, therefore, it was the barbarian plant from the Rha. Cf. Barbarous, Rhaponticine.
Definitions
  1. (Bot.) The name of several large perennial herbs of the genus Rheum and order Polygonaceæ.
  2. The large and fleshy leafstalks of Rheum Rhaponticum and other species of the same genus. They are pleasantly acid, and are used in cookery. Called also pieplant.
  3. (Med.) The root of several species of Rheum, used much as a cathartic medicine.

Webster 1913