A philanthropist is a person who gives money or gifts to charities, or helps needy people in other ways. Famous examples include Andrew Carnegie and Bill & Melinda Gates.
In English, the -ist suffix describes a person who does a particular action. A philanthropist practices philanthropy. Philanthropists are wealthy people with a generous nature and a concern for human welfare. Philanthropy is from Late Latin philanthrōpia, from Greek, from philanthrōpos "humane, kind," from the prefix phil- plus anthrōpos "man, mankind."