A thermometer scale in which each degree Reaumur (°R) is 1/80 of the temperature difference between the freezing point and boiling point of pure water at 1 atmosphere pressure, with 0°R set at the freezing point and 80°R set at the boiling point of water. ... (05 Mar 2000) ... 
[n] - a temperature scale on which water freezes at 0 degrees and boils at 80 degrees
noun a temperature scale on which water freezes at 0 degrees and boils at 80 degrees