The Collaborative International Dictionary of English v.0.48:

Sickle \Sic"kle\, n. [OE. sikel, AS. sicol; akin to D. sikkel,
   G. sichel, OHG. sihhila, Dan. segel, segl, L. secula, fr.
   secare to cut; or perhaps from L. secula. See Saw a cutting
   instrument.]
   1. A reaping instrument consisting of a steel blade curved
      into the form of a hook, and having a handle fitted on a
      tang. The sickle has one side of the blade notched, so as
      always to sharpen with a serrated edge. Cf. Reaping
      hook, under Reap.
      [1913 Webster]

            When corn has once felt the sickle, it has no more
            benefit from the sunshine.            --Shak.
      [1913 Webster]

   2. (Astron.) A group of stars in the constellation Leo. See
      Illust. of Leo.
      [1913 Webster]

   Sickle pod (Bot.), a kind of rock cress (Arabis
      Canadensis) having very long curved pods.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Arabis Canadensis
    n 1: North American rock cress having very long curved pods
         [syn: sicklepod, Arabis Canadensis]