vitamin a1(n = noun.substance) retinol - an unsaturated alcohol that occurs in marine fish-liver oils and is synthesized biologically from carotene; Array
retinol (C20H30O), one of the substances also called vitamin A. It is also called more specifically vitamin A alcohol. It is a required factor for human nutrition. The USP unit of activity is equal to 0.30 micrograms of retinol. [WordNet 1.5]