The Collaborative International Dictionary of English v.0.48:

Very's night signals \Ver"y's night signals\, or Very night
signals \Ver"y night signals\ . [After Lieut. Samuel W. Very,
   who invented the system in 1877.] (Naut.)
   A system of signaling in which balls of red and green fire
   are fired from a pistol, the arrangement in groups denoting
   numbers having a code significance. The pistol used to fire
   the signal flare is called a

   Very pistol.
      [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

Very pistol
    n 1: a pistol for firing Very-light flares [syn: Very pistol,
         Verey pistol]