donor

noun

• a person who donates something, especially money to a fund or charity:an anonymous donor has given $25 [as modifier]:loans from rich donor countries
• a person who provides blood for transfusion, semen for insemination, or an organ or tissue for transplantation.
• Chemistry an atom or molecule that provides electrons in forming a coordinate bond.
• Physics an impurity atom in a semiconductor that contributes a conducting electron to the material.