One who gives or bestows; one who confers anything gratuitously; a benefactor.
- One that contributes something, such as money, to a cause or fund.
- Medicine An individual from whom blood, tissue, or an organ is taken for transfusion, implantation, or transplant.
- Chemistry An atom, molecule, or ion that provides a part to combine with an acceptor, especially an atom that provides two electrons to form a bond with another atom.
- Electronics An element introduced into a semiconductor with a negative valence greater than that of the pure semiconductor.
- Medicine Used for transfusion, implantation, or transplant: a donor organ.