O, n.
more info the blood group whose red cells carry neither the A nor B antigens

O group O type O

sample sentences

"people with type O blood are universal donors"
semantic pointers
more info the 15th letter of the Roman alphabet

O o
more info 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
<noun.substance>   freq. cnt.: 39 freq. cnt.: 39

O atomic number 8 oxygen
lexical pointers
derivationally related form
semantic pointers
substance holonym