Source : Webster's Revised Unabridged Dictionary (1913)

Lariat \Lar"i*at\, v. t. [imp. & p. p. {Lariated}; p. pr. & vb.
   n. {Lariating}.]
   To secure with a lariat fastened to a stake, as a horse or
   mule for grazing; also, to lasso or catch with a lariat.
   [Western U.S.]