O meaning

UK /əʊ/ US /oʊ/ 1 syllable

O (noun): a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust.

O has 3 meanings in this dictionary.

O as a noun

  1. a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust

    Synonyms: oxygen, atomic number 8

    Type of: chemical element, gas

    Kinds: liquid oxygen

  2. the 15th letter of the Roman alphabet

    Type of: letter

  3. the blood group whose red cells carry neither the A nor B antigens
    • people with type O blood are universal donors

    Synonyms: type O, group O

    Type of: blood group

How to pronounce O

O is pronounced /əʊ/ in British English and /oʊ/ in American English. It has 1 syllable.

Words that rhyme with O

More about O on Wikipedia.