SOS
the letters represented by the radio telegraphic signal ( – – – ) used, especially by ships in distress, as an internationally recognized call for help.
SOS
1 Americannoun
verb (used without object)
SOS
2
American
abbreviation
Slang.
s.o.s.
3
American
abbreviation
SOS
British
noun
-
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
Usage
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.
Etymology
Origin of SOS1
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
Origin of s.o.s.3
From Latin sī opus sit
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
An SOS to England's greatest ever batter to clean up the mess made in a London nightclub.
From BBC ● Jun. 10, 2026
Dave sent an SOS to their outfitter and stayed the night with Shelley, hoping for an unlikely rescue, while holding one sleeping bag over them both.
From The Wall Street Journal ● Jun. 1, 2026
Amazon said on Tuesday that it had also reached an agreement with Apple to continue offering the "SOS" functionality on its mobile devices.
From BBC ● Apr. 14, 2026
“Typically, a blockade does not mean a complete shutdown, but rather a disruption to the flow of imports and exports,” said Tim Meehan, security director for assistance in the Americas at International SOS.
From MarketWatch ● Apr. 14, 2026
Princesse wanted to paint the sound that came out of the shell, a moan like a call to a distant ship, an SOS with a dissonant melody.
From "Krik? Krak!" by Edwidge Danticat
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.
