water meter

from WordNet (r) 3.0 (2006)

water meter
    n 1: meter for measuring the quantity of water passing through a
         particular outlet

from The Collaborative International Dictionary of English v.0.48

Water meter \Wa"ter me"ter\
   A contrivance for measuring a supply of water delivered or
   received for any purpose, as from a street main.
   [1913 Webster]