Definition: A poisonous volatile alkaloid derived from tobacco (Nicotiana spp.) and responsible for many of the effects of tobacco; it first stimulates (small doses), then depresses (large doses) at autonomic ganglia and myoneural junctions. Its principal urinary metabolite is cotinine. Nicotine is an important tool in physiologic and pharmacologic investigation, is used as an insecticide and fumigant, and forms salts with most acids.
[Nicotiana, genus name of botanical source, + - ine]
See Also: tobacco