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 McCall’s festoon Caesarean section defloration occipitoparietal fissure inlet contraction antiprotoplasmatic subconscious memory dyspepsia xen(o)