an internationally agreed upon standard, as measured by bioassay, to which samples of a substance, as a drug or hormone, are compared to ascertain their relative potency.
the particular quantity of such a substance, which causes a specific biological effect. Abbreviation: IU
Words nearby international unit
international telecommunications satellite organization, international telecommunications union, international telegram, international temperature scale, international union for conservation of nature, international unit, international workingmen's association, internationale, internationalism, internationalist, internationalize
Origin of international unit
First recorded in 1920–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020
Medical definitions for international unit
The quantity of a biologically active substance, such as a hormone or vitamin, required to produce a specific response.
A unit of potency for similarly active substances, based on this quantity and accepted as an international standard.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Scientific definitions for international unit
A unit for measuring a biologically active substance, such as a hormone or vitamin.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.