WordNet
type O
n. the blood group whose red cells carry neither the A nor B antigens; "people with type O blood are universal donors" [syn: O, group O]
Usage examples of "type o".
If Bree gave him an 0 gene, and you-his father-gave him an 0 gene, he'd show up as type O-his blood won't have any antibodies, and won't react with serum from my blood or from Jamie's or Bree's.