sensor

noun

sen·​sor ˈsen-ˌsȯr  ˈsen(t)-sər 

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

: sense organ

Did you know?

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.

Synonyms of sensor

• detector

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

Individually, advocates encourage San Diegans to turn off their outdoor lights at night or put them on a motion-sensor timer, and talk with their landlords or Home Owners Associations about improving lighting around a property. —Maura Fox, San Diego Union-Tribune, 13 Apr. 2026

Beyond navigation and manipulation, Athen features a suite of sensors that enables it to see practically everything. —New Atlas, 13 Apr. 2026

Using sensors and onboard technology, Waymo vehicles can detect potholes in real time. —Christopher Harris, CBS News, 13 Apr. 2026

These devices are small, expendable sensors dropped into the ocean—usually from aircraft—that act like temporary underwater listening systems, capturing sound signals and transmitting them back for analysis. —Prabhat Ranjan Mishra, Interesting Engineering, 12 Apr. 2026

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

Rhymes for sensor

• censer
• censor
• denser
• fencer
• tensor
• biosensor
• condenser
• dispenser
• extensor

Kids Definition

sensor

noun

sen·​sor ˈsen-ˌsȯ(ə)r 

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

sen·​sor ˈsen-ˌsȯ(ə)r  ˈsen(t)-sər 

: 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