The Collaborative International Dictionary of English v.0.48:

Navy \Na"vy\, a.
   Having a color of navy blue.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Navy blue \Na"vy blue`\, n.
   1. A dark grayish blue. Also called navy.
      [PJC]

   2. Prussian blue. [archaic]
      [Webster 1913 Suppl. +PJC]

The Collaborative International Dictionary of English v.0.48:

Navy \Na"vy\; n.; pl. Navies. [ OF. navie, fr. L. navis ship.
   See Nave of a church.]
   1. A fleet of ships; an assemblage of merchantmen, or so many
      as sail in company. "The navy also of Hiram, that brought
      gold from Ophir." --1 kings x. 11.
      [1913 Webster]

   2. The whole of the war vessels belonging to a nation or
      ruler, considered collectively; as, the navy of Italy.
      [1913 Webster]

   3. The officers and men attached to the war vessels of a
      nation; as, he belongs to the navy.
      [1913 Webster]

   4. same as navy blue.
      [PJC]

   Navy bean. see Bean.

   Navy yard, a place set apart as a shore station for the use
      of the navy. It often contains all the mechanical and
      other appliences for building and equipping war vessels
      and training their crews.
      [1913 Webster]

WordNet (r) 3.0 (2006):

navy
    n 1: an organization of military vessels belonging to a country
         and available for sea warfare [syn: navy, naval forces]
    2: a dark shade of blue [syn: dark blue, navy, navy blue]
    3: the navy of the United States of America; the agency that
       maintains and trains and equips combat-ready naval forces
       [syn: United States Navy, US Navy, USN, Navy]