Nicotine \Nic"o*tine\ (? or ?), n. [F. nicotine. See Nicotian.]

(Chem.) An alkaloid which is the active principle of tobacco. It is a colorless, transparent, oily liquid, having an acrid odor, and an acrid burning taste. It is intensely poisonous. --Ure.

Source: Webster's Revised Unabridged Dictionary (1913)