microgram

noun

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

noun

The millionth part of a gram, being about of a grain troy.

noun

A photograph or a drawing of a microscopic object.

noun

A unit of mass equal to 0.000 001 grams. Symbol: μg or mcg

noun

one millionth (1/1,000,000) gram