Any of various showy herbaceous or shrubby plants of the genus Paeonia (family Paeoniaceae, formerly included in Ranunculaceae), with large globular flowers that are chiefly crimson, pink, or white (often double in cultivation), which are now much grown as ornamental garden plants but were formerly valued chiefly for the supposed medicinal properties of the root, flowers, and seeds. Also: a flower or flowering stem of this plant.——牛津当代大辞典

The seeds of peonies, formerly used for their supposed medicinal properties and as a spice; a peony seed. Obsolete.——牛津当代大辞典

a garden plant with large round flowers that are dark red, white, or pink.——朗文当代大辞典  @en