an internationally recognized distress signal in which the letters SOS are repeatedly spelt out, as by radio-telegraphy: used esp by ships and aircraft
a message broadcast in an emergency for people otherwise unobtainable
informal a call for help
What does SOS mean? The letter sequence SOS (pronounced S-O-S) is used in Morse code as a distress signal—a way to call for help during an emergency, such as on a ship. Morse code uses clicks and pauses, short and long sounds, or flashes of light to represent letters and numbers. S is represented by three short clicks or brief flashes of light, and O is represented by three long sounds or longer flashes of light (depicted with dashes). Morse code can be written out using dots to represent short clicks and dashes to represent long ones, resulting in a specific sequence for SOS (··· – – – ···) that was chosen since it would be easy to communicate with sounds over radio or with flashes of light. The signal became well-known enough that SOS came to be used as an informal term for any call for help or notification that there is an emergency, as in Send an SOS to the board letting them know that we’ll have to schedule an emergency meeting. When used this way, each letter is still pronounced individually (S-O-S). The plural of SOS can be written as SOSs or SOS’s. SOS can also be used as a verb meaning to send such an SOS. Example: I have my phone set up to automatically send an SOS to certain contacts if I ever dial 9-1-1.
First recorded in 1905–10; from the Morse code alphabet, in which three dots (or short clicks) represents the letter S and three dashes (or long clicks) represents the letter O
From Latin sī opus sit
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
I don’t think that I want to take eight bars of so and so’s song and throw them into mine, but the impetus, or the feeling of their song, triggered something in me.
From Los Angeles Times • Sep. 3, 2025
“It’s scary, yes. But so’s giving birth, and I still did that three times,” she laughs, telling me her own callsign is Cherry: “Because of my car, not the tomatoes.”
From BBC • Oct. 15, 2024
Normally when countries break off diplomatic ties with Taiwan the announcement is swift, with Taiwan maybe only getting an hour or so's notice, diplomatic sources told Reuters.
From Reuters • Mar. 22, 2023
At Benta River Falls, an hour or so’s drive away from Mel’s, we were treated to a joyous day at a series of cascading waterfalls and deep pools, led by two energetic guides.
From New York Times • Mar. 9, 2023
Mr. Highgate said, “You gunn have to bring Leroy to me so’s I can tell him what happen.”
From "Elijah of Buxton" by Christopher Paul Curtis
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
