Morse code

American  

noun

1. either of two systems of clicks and pauses, short and long sounds, or flashes of light, used to represent the letters of the alphabet, numerals, etc.: now used primarily in radiotelegraphy by ham operators.

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Morse code British  

noun

1. Also called: international Morse code.  a telegraph code formerly used internationally for transmitting messages; it was superseded by satellite technology (the Global Marine Distress and Safety System) in 1999. Letters, numbers, etc, are represented by groups of shorter dots and longer dashes, or by groups of the corresponding sounds, dits and dahs, the groups being separated by spaces

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Morse code Scientific  

1. A code developed by Samuel Morse used for transmitting messages in which letters of the alphabet and numbers are represented by various sequences of written dots and dashes, or short and long signals such as electric tones or voltages. Morse code was used extensively in telegraphy. In a format that has been standardized for international use, it is still sometimes used for long distance radio communication.

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Etymology

Origin of Morse code

First recorded in 1830–40; after S. F. B. Morse

Example Sentences

You are in the passenger seat with no seat belt, and the dashboard lights are blinking like they’re trying to tell you something in Morse code, which you never learned.

From MarketWatch • Dec. 2, 2025

A thousand small cylindrical acrylic mirrors planted in the sand compose a Morse code poem imagining a dialogue between Tangun, the legendary founder of the first Korean kingdom, and an Egyptian pharaoh.

From Barron's • Nov. 11, 2025

According to Hal Whitehead, who has pioneered research on social organization and cultural transmission in deep-water whales since the 1970s, researchers began studying sperm whale codas by comparing them to Morse code.

From Salon • Aug. 23, 2024

After starting his Army career in Omagh, County Tyrone, he moved to England and worked for a time as a Morse code signaller.

From BBC • Jun. 2, 2024

I spelled out a Morse code message using rocks.

From "The Martian" by Andy Weir