Meaning of tristate

tri•state

Pronunciation: (trī'stāt"), [key]
— adj.
  1. pertaining to a territory made up of three adjoining states: a tristate league.
  2. pertaining to the three adjoining parts of such states: the tristate region of Missouri, Kansas, and Nebraska.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.