mcg

English Thesaurus

1. one millionth (1/1,000,000) gram (noun.quantity)

hypernym	:	metric weight unit, weight unit,
definition	:	a decimal unit of weight based on the gram (noun.quantity)

part holonym	:	nanogram, ng,
definition	:	one billionth (1/1,000,000,000) gram (noun.quantity)

part meronym	:	mg, milligram,
definition	:	one thousandth (1/1,000) gram (noun.quantity)