/ ˈɪntəsteɪt; NAmE -tərs-/ adjective , noun
■ adjective
[ only before noun ] between states, especially in the US :
interstate commerce
■ noun
(also ˌinterstate ˈhighway ) (in the US) a wide road, with at least two lanes in each direction, where traffic can travel fast for long distances across many states. You can only enter and leave interstates at special ramps .
—compare motorway
For more information see the Cultural Guide