megacity

American

[meg-uh-sit-ee] / ˈmɛg əˌsɪt i /

noun

plural

megacities

a city having a population of one million or more.

megacity British

/ ˈmɛɡəˌsɪtɪ /

noun

a city with over 10 million inhabitants

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of megacity

First recorded in 1965–70; mega- + city

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The 32-year-old clothier regularly navigates chaotic traffic to deliver luxury clothes and footwear to customers across the megacity of Lagos, Nigeria's commercial capital.

From Barron's • Apr. 8, 2026

In the high-tech megacity of Shenzhen in southern China, Prince Andrew looked on as dancers spun and waved streamers to entertain an audience of investors and innovators.

From BBC • Feb. 28, 2026

The hosts and Jeff discuss the many reasons Mohammed bin Salman’s outlandish plans for a megacity in the desert have failed to be realized.

From Slate • Nov. 8, 2025

This futuristic Chinese megacity built on mountains seems like science fiction—which is exactly why Florida retirees Bev and John Martin had to see it.

From The Wall Street Journal • Sep. 30, 2025

We are the only megacity in the world that has mountain lions roaming the streets; only Mumbai and its leopards even compare.

From Los Angeles Times • Jan. 12, 2025

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023