A namesake friend; someone, often a complete
stranger whom you might
never have met in person, with whom you chat online, when you feel bored and have nothing
better to do.
I have tons of chatmates on Whatsapp and WeChat.
Even though I haven't met any of them, some of them have become very close to me. Actually, they give my life a new purpose - now, I
don't
even care if I have any traditional brick and mortar buddies. Yes, I know there could be some risk: who knows if my chatmates are mere bots.