1 the 15th letter of the English alphabet: ‘Owl’ begins with an O.
az: ingilis dili əlifbasının on beşinci hərfi
ru: пятнадцатая буква английского алфавита
2 (spoken) zero (used when saying a telephone number): The code for Cambridge is o one two two three.
az: sıfır
ru: ноль
an expression used when speaking to a person, thing etc.
az: o!, ooo! (nida)
ru: о!, ах!, ох!