Rankine is a thermodynamic temperature scale named after the Scottish engineer and physicist William John Macquorn Rankine, who proposed it in 1859.
The symbol is €R (note that this symbol is also used to stand for the Rmer and R￩aumur scales; the symbol €Ra is sometimes used to distinguish it). Like Kelvin, Rankine zero is absolute zero, but Fahrenheit degrees are used. As a result, a difference of 1 R€ is equal to a difference of 1 F€, but 0 €R is −459.67 €F.
The Rankine cycle is an idealised thermodynamic cycle for a steam engine, i.e. one using water as the working fluid.