donor

noun

• 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 found a 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.