the GNU version of the Collaborative International Dictionary of English
n. a vitamin essential for normal vision (C20H30O); it prevents night blindness or inflammation or dryness of the eyes; same as vitamin A. One U.S.P. unit of vitamin A is equivalent to 0.30 micrograms of pure vitamin A alcohol.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes
Word Usage
"Hence vitamin A has received the name of axerophthol."