From WordNet (r) 2.0 (August 2003) [wn]:
runway
n 1: a narrow platform extending from the stage into the audience
in a theater or nightclub etc.
2: a strip of level paved surface where planes can take off and
land
From The Collaborative International Dictionary of English v.0.48 [gcide]:
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]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
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]