a person who donates something, especially money to charity:an anonymous donor has given £25 [as modifier]:loans from rich donor countries
a person who provides blood, an organ, or semen for transplantation, transfusion, etc.:one third of patients die before a suitable donor is founda blood donor
Chemistry an atom or molecule that provides a pair of electrons in forming a coordinate bond.
Physics an impurity atom in a semiconductor which contributes a conducting electron to the material.
