SOS
/ɛsəʊˈɛs
/noun (plural SOSs)
1An international code signal of extreme distress, used especially by ships at sea: they put out an SOS that they were on fire
1.1An urgent appeal for help: I’d thought of phoning a desperate SOS to James
1.2British A message broadcast in an emergency in an attempt to contact a person whose whereabouts are not known: here is an SOS message for Mr Arthur Brown about his brother, who is dangerously ill
abbreviation
Somalian shilling(s).
Origin
Early 20th century: letters chosen as being easily transmitted and recognized in Morse code; by folk etymology an abbreviation of save our souls.