Below is the definition for the word you requested, useful for Scrabble and other word games. To find more definitions please use the dictionary page.
the blood group whose red cells carry neither the A nor B antigens; "people with type O blood are universal donors"
the 15th letter of the Roman alphabet
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