Search microgram (μg, mcg) microgram (μg, mcg) /mī″krəgram/ , a unit of measurement of mass equal to one millionth (10−6) of a gram. See also gram. Tweet Telegram VK Random Words Stryker wedge frame Synalar relative centrifugal force (RCF) syndrome of inappropriate antidiuretic hormone secretion (SIADH) prepatellar bursitis metacommunication oxygen tolerance fMRI mechanism