a viscous fluid, (CH)N(OH)CHCHOH, found in many animal and vegetable tissues, that is a precursor of acetylcholine, lecithin, etc.: usually considered a vitamin of the B complex
Origin:
chol(e)- + -ine
See choline in American Heritage Dictionary 4
noun
A natural amine, C5H15NO2, often classed in the vitamin B complex and a constituent of many other biologically important molecules, such as acetylcholine and lecithin.