The Collaborative International Dictionary of English v.0.48:

Runway \Run"way`\, n.
   1. The channel of a stream.
      [1913 Webster]

   2. The beaten path made by deer or other animals in passing
      to and from their feeding grounds.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

catwalk \catwalk\ n.
   1. A narrow walkway projecting from a stage into the seating
      area of a theater; it is used, e. g. by models displaying
      clothes on it at a fashion show. Called also runway.
      [WordNet 1.5 +PJC]

   2. A narrow walkway high in the air to allow workers access
      to parts of a structure otherwise difficult to reach.
      Catwalks are located, e.g. above a stage in a theater,
      between parts of a building, along the side of a bridge,
      on the outside of a railroad car, on the outside of a
      large storage tank, etc.
      [WordNet 1.5 +PJC]

WordNet (r) 3.0 (2006):

runway
    n 1: a bar or pair of parallel bars of rolled steel making the
         railway along which railroad cars or other vehicles can
         roll [syn: track, rail, rails, runway]
    2: a chute down which logs can slide
    3: a narrow platform extending from the stage into the audience
       in a theater or nightclub etc.
    4: a strip of level paved surface where planes can take off and
       land