What does "interstate" mean?

1. (a major highway) a large, fast highway that connects different states. 2. (between states) involving or connecting two or more states within a country. 3. (moving to another state) to or in another state.

How do you use "interstate"?

Often used with the definite article 'the' or followed by a number, such as 'Interstate 95'. Usually placed before the noun it modifies. Commonly follows verbs of motion like 'move', 'travel', or 'go'.

interstate

n. · adj. · adv.

US //ˌɪntɝˈsteɪt// UK //ˌɪntəstˈeɪt// in·ter·state

1 a major highway (n.)
B1 Intermediate American English

a large, fast highway that connects different states.

a high-speed, multi-lane divided highway that forms part of the national Interstate Highway System in the United States.

Example

We took the interstate for three hours to get to the city.

Example

Traffic on the interstate slowed to a crawl after a heavy snowstorm blocked three lanes near the state border.

Usage

Often used with the definite article 'the' or followed by a number, such as 'Interstate 95'.

Teacher's tip

In the US, 'interstate' is the standard term for these roads, whereas 'motorway' is used in the UK.
- backroad
- local road
2 between states (adj.)
B2 Upper Intermediate American English Academic Law

involving or connecting two or more states within a country.

relating to, connecting, or existing between two or more states, particularly in a federal union.

Example

The company handles interstate trade between New York and New Jersey.

Example

The Supreme Court often hears cases regarding interstate commerce when state laws conflict with federal regulations.

Usage

Usually placed before the noun it modifies.

Teacher's tip

Contrast this with 'intrastate', which refers to things happening within a single state.
- inter state
- national
- intrastate
- local
3 moving to another state (adv.)
B2 Upper Intermediate American English Dialect

to or in another state.

to or in another state within the same country; used to describe travel or relocation.

Example

My sister is moving interstate to start a new job in Brisbane.

Example

Many families chose to relocate interstate during the pandemic in search of more affordable housing and a better lifestyle.

Usage

Commonly follows verbs of motion like 'move', 'travel', or 'go'.

Teacher's tip

This adverbial use is particularly common in Australian English when discussing domestic travel.
- out of state

Origin

From inter- + state, originally as an adjective only; the noun is by (ellipsis) from interstate highway. The noun also serves adjectivally as a (noun adjunct) in such collocations as interstate construction and interstate rest stops.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Last updated June 20, 2026