The letters signified by the signal ( . . . --- . . . ) prescribed by the International Radiotelegraphic Convention of 1912 for use by ships in distress.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). sos. Retrieved September 21, 2026, from http://smartdefine.org/sos/definitions/2064176 |
| Chicago | Webster's. 2011. "sos" http://smartdefine.org/sos/definitions/2064176 (accessed September 21, 2026). |
| Harvard | Webster's 2011, sos, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/sos/definitions/2064176>. |
| MLA | Webster's. "sos" 28 May 2011. Web. 21 September 2026. <http://smartdefine.org/sos/definitions/2064176> |