Formal:
* གྲོགས་པོ། (drokpo) - This is the most common and general term for "friend." It can be used for both male and female friends.
* གྲོགས་མོ། (drokmo) - This is specifically used for a female friend.
* གྲོགས་པ། (drokpa) - This is specifically used for a male friend.
Informal:
* གྲོགས་ (drok) - A shortened version of "གྲོགས་པོ། (drokpo)," often used in casual conversation.
* རོགས་པ། (rokpa) - This is less common than "གྲོགས་པོ། (drokpo)," but it can be used for a close friend or someone you help out often.
Other related terms:
* གྲོགས་རོགས་ (drok-rok) - This means "friends" or "companions."
* གྲོགས་མཐུན་ (drok-thun) - This means "friendship."
Remember: The best way to choose the right term depends on the context and your relationship with the person you're talking about.