Definition of


  1. (noun, body) the blood group whose red cells carry neither the A nor B antigens
  2. (noun, communication) the 15th letter of the Roman alphabet
  3. (noun, substance) 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

via WordNet, Princeton University

Origin of the word O

  1. interj. of fear, surprise, admiration, etc., see oh. more
  2. blood type, 1926, originally "zero," denoting absence of A and B agglutinogens. more

via Online Etymology Dictionary, ©2001 Douglas Harper

Words that sound like O

oahu, oh, ohio, ooh, owe

via soundex() Hash Matches

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Word of the Moment


pertaining to or characterized by the custom of marrying only within the limits of a clan or tribe