ground zero

noun

1

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

2

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

Mingo Junction … sits at ground zero of the longest steelworker strike in American history.

—Michael Janofsky

broadly : center sense 2a

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

—Rich Eisen

3

: the very beginning : square one

We'll have to go back to ground zero and start over.

Synonyms of ground zero

• 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

The public spotlight on what happened may have grown less intense, but the attention will again be turned to ground zero as people gather to read names and remember. — Gloria Pazmino, CNN Money, 8 Aug. 2026

Michigan is ground zero for cyclosporiasis, where more than 10,000 people have eaten something, likely lettuce, contaminated with microscopic pods containing Cyclospora parasites. — Pien Huang, NPR, 2 Aug. 2026

Hawaii was ground zero for the crystal meth epidemic, the first state where the smokable form of the drug really took off. — Guthrie Scrimgeour, Rolling Stone, 2 Aug. 2026

Sanders is nonetheless arriving in Michigan with national Democrats more determined than ever to steer the party in a more pragmatic direction, effectively making the state ground zero for a proxy fight over progressive politics. — David Sivak, The Washington Examiner, 19 July 2026

Word History

First Known Use

1946, in the meaning defined at sense 1

Rhymes for ground zero

• 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