Source : Webster's Revised Unabridged Dictionary (1913)

Stoneroot \Stone"root`\, n. (Bot.)
   A North American plant ({Collinsonia Canadensis}) having a
   very hard root; horse balm. See {Horse balm}, under {Horse}.



   3. Mounted soldiery; cavalry; -- used without the plural
      termination; as, a regiment of horse; -- distinguished
      from foot.

            The armies were appointed, consisting of twenty-five
            thousand horse and foot.              --Bacon.

   4. A frame with legs, used to support something; as, a
      clotheshorse, a sawhorse, etc.

   5. A frame of timber, shaped like a horse, on which soldiers
      were made to ride for punishment.

   6. Anything, actual or figurative, on which one rides as on a
      horse; a hobby.

   7. (Mining) A mass of earthy matter, or rock of the same
      character as the wall rock, occurring in the course of a
      vein, as of coal or ore; hence, to take horse -- said of a
      vein -- is to divide into branches for a distance.

   8. (Naut.)
      (a) See {Footrope}, a.
      (b) A breastband for a leadsman.
      (c) An iron bar for a sheet traveler to slide upon.
      (d) A jackstay. --W. C. Russell. --Totten.

   Note: Horse is much used adjectively and in composition to
         signify of, or having to do with, a horse or horses,
         like a horse, etc.; as, horse collar, horse dealer or
         horse?dealer, horsehoe, horse jockey; and hence, often
         in the sense of strong, loud, coarse, etc.; as,
         horselaugh, horse nettle or horse-nettle, horseplay,
         horse ant, etc.

   {Black horse}, {Blood horse}, etc. See under {Black}, etc.

   {Horse aloes}, caballine aloes.

   {Horse ant} (Zo["o]l.), a large ant ({Formica rufa}); --
      called also {horse emmet}.

   {Horse artillery}, that portion of the artillery in which the
      cannoneers are mounted, and which usually serves with the
      cavalry; flying artillery.

   {Horse balm} (Bot.), a strong-scented labiate plant
      ({Collinsonia Canadensis}), having large leaves and
      yellowish flowers.

   {Horse bean} (Bot.), a variety of the English or Windsor bean
      ({Faba vulgaris}), grown for feeding horses.

   {Horse boat}, a boat for conveying horses and cattle, or a
      boat propelled by horses.

   {Horse bot}. (Zo["o]l.) See {Botfly}, and {Bots}.

   {Horse box}, a railroad car for transporting valuable horses,
      as hunters. [Eng.]

   {Horse} {breaker or trainer}, one employed in subduing or
      training horses for use.

   {Horse car}.
      (a) A railroad car drawn by horses. See under {Car}.
      (b) A car fitted for transporting horses.

   {Horse cassia} (Bot.), a leguminous plant ({Cassia
      Javanica}), bearing long pods, which contain a black,
      catharic pulp, much used in the East Indies as a horse
      medicine.

   {Horse cloth}, a cloth to cover a horse.

   {Horse conch} (Zo["o]l.), a large, spiral, marine shell of
      the genus Triton. See {Triton}.

   {Horse courser}.
      (a) One that runs horses, or keeps horses for racing.
          --Johnson.
      (b) A dealer in horses. [Obs.] --Wiseman.

   {Horse crab} (Zo["o]l.), the Limulus; -- called also
      {horsefoot}, {horsehoe crab}, and {king crab}.

   {Horse crevall['e]} (Zo["o]l.), the cavally.

Source : WordNet®

Collinsonia canadensis
     n : erect perennial strong-scented with serrate pointed leaves
         and a loose panicle of yellowish flowers; the eastern
         United States [syn: {horse balm}, {horseweed}, {stoneroot},
          {stone-root}, {richweed}, {stone root}]