fatberg

noun

fat·​berg ˈfat-ˌbərg How to pronounce fatberg (audio)
plural fatbergs
: a large mass of fat and solid waste that collects in a sewer system
The toxic lump of congealed fat and household waste—known as a fatberg—was 40 metres long and so heavy that it broke the 1940s-era sewer.Rebecca Ratcliffe
Restaurants are a big contributor to fatbergs: Thames Water, the London utilities company, found nine out of 10 fast-food eateries lacked adequate grease traps to stop fat from entering the sewers.Eve Watling

Examples of fatberg in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Better pipes = fewer fatbergs For the second part of their one-two punch, engineers from the same research center developed a new coating for the interior walls of sewer pipes. Abhimanyu Ghoshal, New Atlas, 25 Aug. 2025 In 2019, a 40-ton fatberg in London took three weeks to clear with eight people working nine hours each day on the task. Laura Baisas, Popular Science, 21 Aug. 2025 The sewer has a fatberg. Will Pritchard, Wired, 13 Nov. 2021

Word History

Etymology

fat entry 3 + (ice)berg

First Known Use

2008, in the meaning defined above

Time Traveler
The first known use of fatberg was in 2008

Browse Nearby Words

Cite this Entry

“Fatberg.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fatberg. Accessed 11 Sep. 2025.

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!