A person of blood group O, who can in theory donate blood to recipients of any ABO blood group.
More example sentences
- It's O negative blood that makes a universal donor.
- People with ‘O’ type blood are universal donors.
- As blood group O negative we are, apparently, much in demand as universal donors, and the blood service is more than welcome to as much of the stuff as they can safely pump out of us.
Definition of universal donor in:
- The US English dictionary