ri·​cin ˈrī-sᵊn How to pronounce ricin (audio)
: a poisonous protein in the castor bean

Examples of ricin in a Sentence

Recent Examples on the Web Bahne Stechmann at the Curie Institute has discovered the first small molecule that protects mice against ricin. Ed Yong, Discover Magazine, 30 Dec. 2010 Craven struggles to recall all of the cases she's had a hand in, but a few come to mind, like a criminal case involving a New Boston, Texas, woman who sent letters laced with poisonous ricin to the U.S. president and others. Arkansas Online, 31 May 2022 There have been several incidents in recent years involving ricin being sent through the mail. CBS News, 19 Sep. 2020 In his truck, officers found a plastic water gun and five tubes that tested positive for ricin. Amanda Rabines, Orlando Sentinel, 10 May 2022 At the hearing, Demissie said his client never made ricin, the Globe reported. Washington Post, 5 Apr. 2022 In 2018, a letter that claimed to contain ricin led to a full biohazard response by first responders at her home. Fox News, 11 May 2022 The seed for Saaem’s ricin idea didn’t involve him at all. Washington Post, 5 Apr. 2022 One example is ricin, which is produced naturally in castor seeds and is lethal to humans in the tiniest amounts. Amy Webb, The Atlantic, 14 Feb. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ricin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin ricinus castor-oil plant

First Known Use

1896, in the meaning defined above

Time Traveler
The first known use of ricin was in 1896

Dictionary Entries Near ricin

Cite this Entry

“Ricin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ricin. Accessed 21 Feb. 2024.

Medical Definition


: a poisonous protein in the castor bean

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