The Collaborative International Dictionary of English v.0.48:

Cymbiform \Cym"bi*form\ (s?m"b?-f?rm),, a. [L. cymba boat (Gr.
   ????) + -form: cf. F. cymbiforme.]
   Shaped like a boat; (Bot.) elongated and having the upper
   surface decidedly concave, as the glumes of many grasses.
   [1913 Webster]