Source : Webster's Revised Unabridged Dictionary (1913)

Sagebrush \Sage"brush`\, n.
   A low irregular shrub ({Artemisia tridentata}), of the order
   {Composit[ae]}, covering vast tracts of the dry alkaline
   regions of the American plains; -- called also {sagebush},
   and {wild sage}.

Source : WordNet®

sagebrush
     n : any of several North American composite subshrubs of the
         genera Artemis or Seriphidium [syn: {sage brush}]