friend

noun:a person with whom one has a close personal relationship, characterized by mutual trust, affection, and support
- She turned to her friend for advice during the difficult transition.
noun:an ally or advocate for a cause, group, or idea
- He has always been a friend of environmental conservation, volunteering for clean‑up projects.
verb:to add someone as a contact or follower in an online social networking service
- I decided to friend my new coworker on the professional networking site.