The Collaborative International Dictionary of English v.0.48:

Tomahawk \Tom"a*hawk\, n. [Of American Indian origin; cf.
   Algonkin tomehagen, Mohegan tumnahegan, Delaware tamoihecan.]
   A kind of war hatchet used by the American Indians. It was
   originally made of stone, but afterwards of iron.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tomahawk \Tom"a*hawk\, v. t. [imp. & p. p. Tomahawked; p. pr.
   & vb. n. Tomahawking.]
   To cut, strike, or kill, with a tomahawk.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tomahawk
    n 1: weapon consisting of a fighting ax; used by North American
         Indians [syn: tomahawk, hatchet]
    v 1: cut with a tomahawk
    2: kill with a tomahawk