The Collaborative International Dictionary of English v.0.48:

Scurvy \Scur"vy\, n. [Probably from the same source as scorbute,
   but influenced by scurf, scurfy, scurvy, adj.; cf. D.
   scheurbuik scurvy, G. scharbock, LL. scorbutus. Cf.
   Scorbute.] (Med.)
   A disease characterized by livid spots, especially about the
   thighs and legs, due to extravasation of blood, and by spongy
   gums, and bleeding from almost all the mucous membranes. It
   is accompanied by paleness, languor, depression, and general
   debility. It is occasioned by confinement, innutritious food,
   and hard labor, but especially by lack of fresh vegetable
   food, or confinement for a long time to a limited range of
   food, which is incapable of repairing the waste of the
   system. It was formerly prevalent among sailors and soldiers.
   [1913 Webster]

   Scurvy grass [Scurvy + grass; or cf. Icel. skarfak[=a]l
      scurvy grass.] (Bot.) A kind of cress (Cochlearia
      officinalis) growing along the seacoast of Northern
      Europe and in arctic regions. It is a remedy for the
      scurvy, and has proved a valuable food to arctic
      explorers. The name is given also to other allied species
      of plants.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scurvy grass
    n 1: a widely distributed Arctic cress reputed to have value in
         treatment or prevention of scurvy; a concentrated source of
         vitamin C [syn: scurvy grass, common scurvy grass,
         Cochlearia officinalis]
    2: any plant of the genus Barbarea: yellow-flowered Eurasian
       cresses; widely cultivated for winter salad [syn: winter
       cress, St. Barbara's herb, scurvy grass]