o - definition and synonyms

noun 

Your browser doesn’t support HTML5 audio

/əʊ/
singularo
pluralo’s
singularO
pluralO’s

or O 

Your browser doesn’t support HTML5 audio

  1. 1
    [countable/uncountable] the 15th letter of the English alphabet. O is a vowel.
     Synonyms and related words
  2. 2
    [countable/uncountable] spoken a way of sayingzero’, used for example when you are telling someone a telephone number or saying a date such as 1904
     Synonyms and related words
  3. 3

    O

    [uncountable] medical a common blood group in the ABO system