The Collaborative International Dictionary of English v.0.48:

Curcuma \Cur"cu*ma\ (k?r"k?-m?), n. [Cf. F., It., & Sp. curcuma;
   all fr. Ar. kurkum. Cf. Turmeric.] (Bot.)
   A genus of plants of the order Scitamine[ae], including the
   turmeric plant (Curcuma longa).
   [1913 Webster]

   Curcuma paper. (Chem.) See Turmeric paper, under
      Turmeric.
      [1913 Webster]