Definition of "microgram" [microgram]

• A unit of mass equal to one thousandth (10-3) of a milligram or one millionth (10-6) of a gram. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It takes 1000 grams to make a kilogram, so that means a microgram is a billionth of a kilogram."
• "Each dose contains 50 micrograms (a microgram is one-millionth of a gram and a gram is the weight of one-fifth of a teaspoon of water)."
• "A microgram is a millionth of a gram; a deciliter is one-tenth of a liter."