SOS Definition

SOS
noun SOSs

1. An internationally recognized distress call that is put out by a ship's or aircraft's radio-telegraphy system and which consists of these three letters repeatedly transmitted in Morse code.
2. colloq
Any call for help.

Etymology: Early 20c: in folk etymology, it is often popularly believed that this is an abbreviated form of Save Our Souls, but these three letters (represented by three dots, three dashes and three dots) were actually chosen because, in Morse code, they are the easiest to transmit and recognize.