rotor
n. countablen. a part of a machine that spins around. You usually find it in things like helicopters, engines, or fans to help them move or create power.
n. a rotating part of a mechanical device, such as an electric motor, generator, or turbine. In aviation, refers specifically to the system of rotating blades that provides lift and propulsion for a helicopter.
The helicopter's rotor started to spin faster.
Engineers inspected the tail rotor for cracks after the pilot reported unusual vibrations during the landing.
The efficiency of a wind turbine depends largely on the aerodynamic design of its rotor, which must capture maximum kinetic energy from varying wind speeds.
From an irregular clipping of rotator, originally in mathematics, coined by English mathematician and philosopher William Kingdon Clifford based on vector, see quotations. Doublet of rota and ruote.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Often used in technical or engineering contexts; frequently appears in compound nouns like 'tail rotor' or 'rotor blade'.
Last updated May 6, 2026