contributor

noun

1. A benefactor; someone who donates to charity or some cause.

   “I am a longstanding financial contributor to Amnesty International.”

2. A person who backs, supports or champions a cause, activity or institution.

   “He was a regular contributor to Greenpeace protests.”

   “The nation lost two major contributors to the cause of human rights in the murders of Mayor George Moscone and Supervisor Harvey Milk on Nov. 27.”

3. A person (or thing) instrumental in the creation or growth of something.

   “Methane is a major contributor to global warming”

4. A person who produces articles published in a newspaper, magazine, online publication, etc.

   “William Safire has been a notable contributor to the op-ed pages of The New York Times for many years.”