D defs.my
Entry 1 sense Webster, 1913

Water thermometer

/wôt'-ẽr thẽrm-äm'-ət-ẽr/ · Wa·ter ther·mom·e·ter · IPA
01 A thermometer filled with water instead of mercury, for ascertaining the precise temperature at which water attains its maximum density. Th…
  1. 1.
    A thermometer filled with water instead of mercury, for ascertaining the precise temperature at which water attains its maximum density. This is about 39° Fahr., or 4° Centigrade; and from that point down to 32° Fahr., or 0° Centigrade, or the freezing point, it expands.(Physics)