[ men-uh-dahy-ohn ]
/ ˌmɛn əˈdaɪ oʊn /

noun Pharmacology.

a synthetic yellow crystalline powder, C11H8O2, insoluble in water, used as a vitamin K supplement.


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Also called vitamin K3.

Origin of menadione

First recorded in 1940–45; me(thyl) + na(phthalene) + di-1 + -one Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for menadione

/ (ˌmɛnəˈdaɪəʊn) /


a yellow crystalline compound used in fungicides and as an additive to animal feeds. Formula: C 11 H 8 O 2Also: vitamin K 3

Word Origin for menadione

C20: from me (thyl) + na (phtha) + di- 1 + -one
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

Medical definitions for menadione

[ mĕn′ə-dīōn′ ]


A synthetic vitamin K derivative occurring as a yellow crystalline powder and used as a vitamin K supplement.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.