bio·​cide | \ ˈbī-ə-ˌsīd How to pronounce biocide (audio) \

Definition of biocide

: a substance (such as an algicide or fungicide) that destroys or inhibits the growth or activity of living organisms Sodium azide is an explosive, broad-spectrum biocide with toxicity comparable to sodium cyanide's.— Science News

Examples of biocide in a Sentence

Recent Examples on the Web Another target is to cut pollution from biocides, plastic wastes, and excess nutrients by at least 50%. Jessie Yeung, CNN, "We have 10 years to save Earth's biodiversity as mass extinction caused by humans takes hold, UN warns," 14 Jan. 2020 Waterford masks contain a biocide that protects medical workers and other wearers from infectious diseases better than existing masks, which were designed more to safeguard patients than wearers, the company says. Joseph A. Mann Jr, miamiherald, "Laser Guardian aims to keep lasers safe | Miami Herald," 9 Mar. 2018 A class of biocides known as quaternary ammonium compounds, or quats, is one chemical treatment that temporarily diminishes biofilms and their visible effects. National Geographic, "Black Slime Is Coating World Monuments—And That May Be Good," 21 Sep. 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'biocide.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of biocide

1947, in the meaning defined above

Keep scrolling for more

Learn More about biocide

Time Traveler for biocide

Time Traveler

The first known use of biocide was in 1947

See more words from the same year

Statistics for biocide

Cite this Entry

“Biocide.” Dictionary, Merriam-Webster, Accessed 17 Jan. 2021.

Keep scrolling for more

More Definitions for biocide


bio·​cide | \ ˈbī-ə-ˌsīd How to pronounce biocide (audio) \

Medical Definition of biocide

: a substance (as glutaraldehyde) that is destructive to many different organisms

Other Words from biocide

biocidal \ ˌbī-​ə-​ˈsīd-​ᵊl How to pronounce biocide (audio) \ adjective

Comments on biocide

What made you want to look up biocide? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Words of Snow and Ice Quiz

  • image1037863653
  • Which of the following refers to thin, bending ice, or to the act of running over such ice?
True or False

Test your knowledge - and maybe learn something along the way.


Anagram puzzles meet word search.

Love words? Need even more definitions?

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