tristate
adjective
1. Having, or pertaining to, three distinct states.
- This tristate logic deals with true, false, and unknown values.
2. Of, pertaining to, or characteristic of a region in the United States where three state borders come to a single point.
- The event will be sponsored by several tristate businesses.
noun
1. The area in some regions of the United States where three state borders come to a single point.
- The Tristate is on alert after a rash of home burglaries.