Source : Webster's Revised Unabridged Dictionary (1913)

Guillotine \Guil"lo*tine`\ (g[i^]l"l[-o]*t[=e]n`), n. [F., from
   Guillotin, a French physician, who proposed, in the
   Constituent Assembly of 1789, to abolish decapitation with
   the ax or sword. The instrument was invented by Dr. Antoine
   Louis, and was called at first {Louison} or {Louisette}.
   Similar machines, however, were known earlier.]
   1. A machine for beheading a person by one stroke of a heavy
      ax or blade, which slides in vertical guides, is raised by
      a cord, and let fall upon the neck of the victim.

   2. Any machine or instrument for cutting or shearing,
      resembling in its action a guillotine.

Guillotine \Guil"lo*tine`\ (g[i^]l`l[-o]*t[=e]n"), v. t. [imp. &
   p. p. {Guillotined}; p. pr. & vb. n. {Guillotining}.] [Cf. F.
   guillotiner.]
   To behead with the guillotine.

Source : WordNet®

guillotine
     n 1: closure imposed on the debate of specific sections of a bill
          [syn: {closure by compartment}]
     2: instrument of execution that consists of a weighted blade
        between two vertical poles; used for beheading people
     v : kill by cutting the head off with a guillotine; "The French
         guillotined many Vietnamese while they occupied the
         country"