rheostat

As a noun rheostat

is rheostat.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between reostat and rheostat

is that reostat is dated form of rheostat while rheostat is an electrical resistor, with two terminals, whose resistance is continuously variable by moving a knob or slider.

As nouns the difference between taxonomy and rheostat

is that taxonomy is the science or the technique used to make a classification while rheostat is rheostat.

As a noun rheostat

is an electrical resistor, with two terminals, whose resistance is continuously variable by moving a knob or slider.

As an adjective rheostatic is

regulated using a rheostat.