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Definition of Mcg
1. Noun. One millionth (1/1,000,000) gram. 
Exact synonyms: Microgram
Generic synonyms: Metric Weight Unit, Weight Unit
Group relationships: Mg, Milligram
Terms within: Nanogram, Ng
Generic synonyms: Metric Weight Unit, Weight Unit
Group relationships: Mg, Milligram
Terms within: Nanogram, Ng
Medical Definition of Mcg
1. A microgram, one-millionth of a gram. (27 Sep 1997)



