cathode ray

American  

noun

1. a flow of electrons emanating from a cathode in a vacuum tube and focused into a narrow beam.

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cathode ray Scientific  

1. A beam of electrons streaming from the negatively charged end of a vacuum tube (the cathode) toward a positively charged plate (the anode).

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Etymology

Origin of cathode ray

First recorded in 1875–80

Example Sentences

See Examples For:

cathode ray

At first, we don’t quite know when we are — the TV sets are cathode ray, the phones are landlines and a cigarette machine sits in the town bar.

From Los Angeles Times ● Apr. 28, 2026

“It’ll come sooner,” he said, standing between the computers controlling the sluice gates and an old cathode ray tube TV set.

From Washington Post ● Oct. 30, 2021

The cathode ray tube was broken, and the screen displayed only a single white line on a black background.

From New York Times ● Nov. 1, 2019

Thomson’s cathode ray tube showed that atoms contain small, negatively charged particles called electrons.

From Textbooks ● Feb. 14, 2019

They had discovered the X ray, the cathode ray, the electron, and radioactivity, invented the ohm, the watt, the Kelvin, the joule, the amp, and the little erg.

From "A Short History of Nearly Everything" by Bill Bryson