Word Origin
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 Show More
Origin of international unit First recorded in 1920–25
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
international unit in Medicine 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. Show More
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
international unit in Science A unit for measuring a biologically active substance, such as a hormone or vitamin. Show More
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
