rotor

noun

ro·​tor ˈrō-tər 

1

a

: a part that revolves in a stationary part

a brake rotor

b

: the rotating member of an electrical machine

2

: an assembly of rotating blades that supplies lift or stability for a rotorcraft

Examples of rotor in a Sentence

Recent Examples on the Web

Super-low aircraft noise As per Moble Benedict, PhD, an associate professor of aerospace engineering at Texas A&M University and CEO of Harmony Aeronautics, the prototype features a proprietary coaxial rotor design. —Georgina Jedikovska, Interesting Engineering, 16 Feb. 2026

Tektro 4-piston hydraulic brakes with 180mm rotors deliver precise, fade-free braking even on fast descents and steep terrain. —New Atlas, 13 Feb. 2026

The movement, made by LVMH sister brand Zenith, is the El Primero 400 chronograph movement, customized with a carving on the rotor of the brand’s famous Bird on a Rock brooch. —Carol Besler, Robb Report, 6 Feb. 2026

The noise could be a dust shield behind one of the brake rotors that is rubbing. —John Paul Senior Manager Public Affairs and Traffic Safety Aaa Northeast, Hartford Courant, 5 Feb. 2026

Word History

Etymology

contraction of rotator

First Known Use

1892, in the meaning defined at sense 1a

Phrases Containing rotor

• tilt-rotor

Rhymes for rotor

• boater
• floater
• motor
• voter
• locomotor
• psychomotor
• servomotor
• vasomotor
• oculomotor
• sensorimotor
• premotor
• promoter

Kids Definition

rotor

noun

ro·​tor ˈrōt-ər 

1

: a part that rotates in a stationary part (as in an electrical machine)

2

: a complete system of rotating blades that support a helicopter in flight