See tribe in Webster's New World College Dictionary
noun
esp. among preliterate peoples, a group of persons, families, or clans believed to be descended from a common ancestor and forming a close community under a leader, or chief
a group of this kind having recognized ancestry; specif.,
any of the three divisions of the ancient Romans, traditionally of Latin, Sabine, and Etruscan origin
any of the later political and territorial divisions of the ancient Romans
any of the phylae of ancient Greece
any of the twelve divisions of the ancient Israelites
any group of people having the same occupation, habits, ideas, etc.: often in a somewhat derogatory sense: the tribe of drama critics
a taxonomic category that is a subdivision of a subfamily of plants or animals and consists of several closely related genera
a natural group of plants or animals classified together without regard for their taxonomic relations
in stock breeding, the animals descended from the same female through the female line
Informal a family, esp. a large one
See tribe in American Heritage Dictionary 4
(trīb)
noun
A unit of sociopolitical organization consisting of a number of families, clans, or other groups who share a common ancestry and culture and among whom leadership is typically neither formalized nor permanent.
A political, ethnic, or ancestral division of ancient states and cultures, especially:
a. Any of the three divisions of the ancient Romans, namely, the Latin, Sabine, and Etruscan.
b. Any of the 12 divisions of ancient Israel.
c. A phyle of ancient Greece.
A group of people sharing an occupation, interest, or habit: a tribe of graduate students.
Informal A large family.
Biology A taxonomic category placed between a subfamily and a genus or between a suborder and a family and usually containing several genera.