The Collaborative International Dictionary of English v.0.48:

Manihoc \Man"i*hoc\, Manihot \Man"i*hot\, n.
   See Manioc.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Manioc \Ma"ni*oc\, n. [Pg. mandioca, fr. Braz.] (Bot.)
   The tropical plants (Manihot utilissima, and Manihot
   Aipi), from which cassava and tapioca are prepared; also,
   cassava. [Written also mandioc, manihoc, manihot.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

Manihot
    n 1: genus of economically important tropical plants: cassava
         [syn: Manihot, genus Manihot]