Source : Webster's Revised Unabridged Dictionary (1913)

Machinate \Mach"i*nate\, v. i. [imp. & p. p. {Machinated}; p.
   pr. & vb. n. {Machinating}.] [L. machinatus, p. p. of
   machinari to devise, plot. See {Machine}.]
   To plan; to contrive; esp., to form a scheme with the purpose
   of doing harm; to contrive artfully; to plot. ``How long will
   you machinate!'' --Sandys.

Machinate \Mach"i*nate\, v. t.
   To contrive, as a plot; to plot; as, to machinate evil.

Source : WordNet®

machinate
     v 1: arrange by systematic planning and united effort; "machinate
          a plot"; "organize a strike"; "devise a plan to take
          over the director's office" [syn: {organize}, {organise},
           {prepare}, {devise}, {get up}]
     2: engage in plotting or enter into a conspiracy, swear
        together; "They conspired to overthrow the government"
        [syn: {conspire}, {cabal}, {complot}, {conjure}]