1. 
[syn: marathoner, marathon runner, road runner, long-distance runner]
The Collaborative International Dictionary of English v.0.48:
Road \Road\ (r[=o]), n. [AS. r[=a]d a riding, that on which one
   rides or travels, a road, fr. r[imac]dan to ride. See Ride,
   and cf. Raid.]
   1. A journey, or stage of a journey. [Obs.]
      [1913 Webster]
            With easy roads he came to Leicester. --Shak.
      [1913 Webster]
   2. An inroad; an invasion; a raid. [Obs.] --Spenser.
      [1913 Webster]
   3. A place where one may ride; an open way or public passage
      for vehicles, persons, and animals; a track for travel,
      forming a means of communication between one city, town,
      or place, and another.
      [1913 Webster]
            The most villainous house in all the London road.
                                                  --Shak.
      [1913 Webster]
   Note: The word is generally applied to highways, and as a
         generic term it includes highway, street, and lane.
         [1913 Webster]
   4. [Possibly akin to Icel. rei[eth]i the rigging of a ship,
      E. ready.] A place where ships may ride at anchor at some
      distance from the shore; a roadstead; -- often in the
      plural; as, Hampton Roads. --Shak.
      [1913 Webster]
            Now strike your saile, ye jolly mariners,
            For we be come unto a quiet rode [road]. --Spenser.
      [1913 Webster]
   On the road, or Uponthe road, traveling or passing over a
      road; coming or going; traveling; on the way.
      [1913 Webster]
            My hat and wig will soon be here,
            They are upon the road.               --Cowper.
      [1913 Webster]
   Road agent, a highwayman, especially on the stage routes of
      the unsettled western parts of the United States; -- a
      humorous euphemism. [Western U.S.]
      [1913 Webster]
            The highway robber -- road agent he is quaintly
            called.                               --The century.
      [1913 Webster]
   Road book, a guidebook in respect to roads and distances.
   road kill See roadkill in the vocabulary.
   Road metal, the broken, stone used in macadamizing roads.
   Road roller, a heavy roller, or combinations of rollers,
      for making earth, macadam, or concrete roads smooth and
      compact. -- often driven by steam.
   Road runner (Zool.), the chaparral cock.
   Road steamer, a locomotive engine adapted to running on
      common roads.
   To go on the road, to engage in the business of a
      commercial traveler. [Colloq.]
   To take the road, to begin or engage in traveling.
   To take to the road, to engage in robbery upon the
      highways.
      [1913 Webster]
   Syn: Way; highway; street; lane; pathway; route; passage;
        course. See Way.
        [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Chaparral \Cha`par*ral"\, n. [Sp., fr. chaparro an evergeen
   oak.]
   1. A thicket of low evergreen oaks.
      [1913 Webster]
   2. An almost impenetrable thicket or succession of thickets
      of thorny shrubs and brambles.
      [1913 Webster]
   Chaparral cock; fem. Chaparral hen (Zool.), a bird of the
      cuckoo family (Geococcyx Californianus), noted for
      running with great speed. It ranges from California to
      Mexico and eastward to Texas; -- called also road
      runner, ground cuckoo, churea, and snake killer. It
      is the state bird of New Mexico.
      [1913 Webster +PJC] chapati
WordNet (r) 3.0 (2006):
road runner
    n 1: someone who participates in long-distance races (especially
         in marathons) [syn: marathoner, marathon runner, road
         runner, long-distance runner]