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
Finally, Ford integrated the magnets into its EV motor rotors for durability testing.
—
Aman Tripathi, Interesting Engineering, 20 May 2026
In March, engineers at NASA's Jet Propulsion Laboratory (JPL) in Southern California completed tests on rotor designs that could be used to fly those drones, spinning the experimental helicopter blades fast enough for their tips to exceed Mach 1 (the speed of sound).
—Josh Dinner, Space.com, 17 May 2026
The repairs were performed, but the price seemed a bit excessive—nearly $700 for just the rear brake replacement, including pads and rotors.
—John Paul Senior Manager Public Affairs and Traffic Safety Aaa Northeast, Hartford Courant, 16 May 2026
Braking comes in the form of DOT hydraulic brakes with six-piston calipers and large 220-mm rotors.
—New Atlas, 15 May 2026
See All Example Sentences for rotor
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Aman Tripathi, Interesting Engineering, 20 May 2026
In March, engineers at NASA's Jet Propulsion Laboratory (JPL) in Southern California completed tests on rotor designs that could be used to fly those drones, spinning the experimental helicopter blades fast enough for their tips to exceed Mach 1 (the speed of sound).
—Josh Dinner, Space.com, 17 May 2026
The repairs were performed, but the price seemed a bit excessive—nearly $700 for just the rear brake replacement, including pads and rotors.
—John Paul Senior Manager Public Affairs and Traffic Safety Aaa Northeast, Hartford Courant, 16 May 2026
Braking comes in the form of DOT hydraulic brakes with six-piston calipers and large 220-mm rotors.
—New Atlas, 15 May 2026
See All Example Sentences for rotor
Cite this Entry
“Rotor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rotor. Accessed 30 May. 2026.
Copy CitationKids 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
Love words? Need even more definitions?
Merriam-Webster unabridged
