o

1. the blood group whose red cells carry neither the A nor B antigens; "people with type O blood are universal donors"
2. the 15th letter of the Roman alphabet
3. 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

Synonyymit

Hierarkia