a social division in a traditional society consisting of families or communities linked by social, economic, religious, or blood ties, with a common culture and dialect, typically having a recognized leader.
We grew up in Port Harcourt, Rivers State, and maybe because we were sheltered, we didn't "see" tribes. We simply had friends who had villages different from ours, but there was no division based on where your origin was. Little did I know that there was great animosity between tribes, especially when it came to marriage. Some parents even demand that their children marry someone from the same village! You would think this attitude would remain in Nigeria, but it has trickled down to Nigerians in the diaspora. Watch Tammy's episode on Inter-tribal Dating, where young Nigerians in America speak on the topic.
My parents are from different tribes; Cakes is from yet a different tribe; my sister's husband is from another different tribe (and he's even extra because he has Ghanaian and Welsh blood) - so obviously, in our family we don't really "see" tribe. Don't get me wrong, we are well aware of the differences, but choose to see a person over their state of origin. Meanwhile, I'm still waiting for my interview with Kachi on inter-tribal marriage. :-|
P.S. I was going to link to the list of tribes I saw online, but my tribe is listed incorrectly and I'm offended.