sensor

noun

1
: a device that responds to a physical stimulus (such as heat, light, sound, pressure, magnetism, or a particular motion) and transmits a resulting impulse (as for measurement or operating a control)
2

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Sensors are used today almost everywhere. Radar guns bounce microwaves off moving cars. A burglar alarm may use a photosensor to detect when a beam of light has been broken, or may use ultrasonic sound waves that bounce off moving objects. Still other sensors may detect pressure (barometers) or chemicals (Breathalyzers and smoke detectors). Stud finders, used by carpenters to locate wooden studs under a wall, may employ magnets or radar. Wired gloves, which relay information about the position of the fingers, are used in virtual-reality environments. A cheap car alarm may be nothing but a shock sensor, in which a strong vibration will cause two metal surfaces to come together.

Examples of sensor in a Sentence

Image sensors are used in digital cameras. Infrared sensors can track an object's movement.
Recent Examples on the Web
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.
The feeder has anti-jam technology, low food detection sensors, and a backup battery in case of power failure. Molly Higgins, Wired News, 11 July 2025 New missions are being designed to process data directly in space using AI, quantum sensors and edge computing. Daisy Dobrijevic, Space.com, 11 July 2025 These systems usually involve monitoring rainfall, water levels, and stream flow through sensors inside and out of the water and automated reporting to a central station, Tardy said. Terry Collins, USA Today, 11 July 2025 Last year, the firehouse was given a new siren, while an old siren was refurbished and moved to Comfort Park, where officials hooked it up to a U.S. Geological Survey sensor at Cypress Creek, the AP. Brenton Blanchet, People.com, 11 July 2025 See All Example Sentences for sensor

Word History

Etymology

Latin sentire to perceive + English -or entry 1 — more at sense

First Known Use

circa 1928, in the meaning defined at sense 1

Time Traveler
The first known use of sensor was circa 1928

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Cite this Entry

“Sensor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/sensor. Accessed 14 Jul. 2025.

Kids Definition

sensor

noun
sen·​sor ˈsen-ˌsȯ(ə)r How to pronounce sensor (audio)
ˈsen(t)-sər
: a device that detects a physical quantity (as a movement or a beam of light) and responds by transmitting a signal

Medical Definition

sensor

noun
: a device that responds to a physical stimulus (as heat, light, sound, pressure, magnetism, or a particular motion) and transmits a resulting impulse (as for measurement or operating a control)
also : sense organ

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