Source : Webster's Revised Unabridged Dictionary (1913)

R'eaumur \R['e]`au`mur"\, a.
   Of or pertaining to Ren['e] Antoine Ferchault de R['e]aumur;
   conformed to the scale adopted by R['e]aumur in graduating
   the thermometer he invented. -- n. A R['e]aumur thermometer
   or scale.

   Note: The R['e]aumur thermometer is so graduated that 0[deg]
         marks the freezing point and 80[deg] the boiling point
         of water. Frequently indicated by R. Cf. {Centigrade},
         and {Fahrenheit}. See Illust. of {Thermometer}.