noun
: a quantity of a biological (as a vitamin, hormone, antibiotic, antitoxin) or its equivalent based on bioassay that produces a particular biological effect agreed upon internationally
noun
: a quantity of a biological (as a vitamin, hormone, antibiotic, antitoxin) or its equivalent based on bioassay that produces a particular biological effect agreed upon internationally
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012