donor

noun3

1. •
   someone who gives money, goods or a part of their body to help others

   • The charity raised $2,000 from various donors.
   • The hospital is seeking an organ donor.
2. •
   An object, typically broken beyond repair, that is used for spare parts.

   • You'll need to lengthen the plug for the fan switch and swap its connector for that of the donor. — 2004
3. •
   A group or molecule that donates either a radical, electrons or a moiety in a chemical reaction. Compare acceptor.