ground zero

noun

1

: the point directly above, below, or at which a nuclear explosion occurs

2

: the center or origin of rapid, intense, or violent activity or change

broadly : center sense 2a

the party town that served as ground zero for those corporate … bashes

—Rich Eisen

3

: the very beginning : square one

Synonyms

• center
• capital
• hub
• mecca
• focus
• base
• nucleus
• core
• seat
• nerve center
• heart

Examples of ground zero in a Sentence

ground zero in the battle over immigration laws

a city that was once ground zero for the insurance industry

Recent Examples on the Web

Next season’s Eastern Conference will be ground zero of the NBA’s parity gambit, molded into the shape of competition the league set in motion over the past half-decade. —Jared Weiss, New York Times, 8 July 2025

Kansas City isn’t exactly ground zero for Oklahoma City Thunder fandom, but the NBA team does have support in the area. —Pete Grathoff, Kansas City Star, 30 June 2025

Indiana is ground zero for the growth of the WNBA, thanks to the arrival of Caitlin Clark as the No. 1 draft pick in 2024. —Kurt Badenhausen, Sportico.com, 24 June 2025

That distinction falls to the Bay Area — ground zero for Democratic politics and pro-immigrant rights. —Max Taves, Mercury News, 11 June 2025

Word History

First Known Use

1946, in the meaning defined at sense 1

Rhymes for ground zero

• nonzero
• subzero
• biro
• spiro
• superhero

Kids Definition

ground zero

noun

1

: the site of a nuclear explosion

2

: the center of rapid, intense, or violent activity or change

3

: the very beginning : square one