Wordnet 3.0
NOUN (2)
1. 
 a high narrow platform above a deck or in an engine room or boiler room; 
2. 
 the highest navigational bridge on a ship; 
 a small (often open) deck above the pilot house; 
[syn: flying bridge, flybridge, fly bridge, monkey bridge]
WordNet (r) 3.0 (2006):
monkey bridge
    n 1: a high narrow platform above a deck or in an engine room or
         boiler room
    2: the highest navigational bridge on a ship; a small (often
       open) deck above the pilot house [syn: flying bridge,
       flybridge, fly bridge, monkey bridge]