nicotine Meaning, Definition & Usage

  1. noun an alkaloid poison that occurs in tobacco; used in medicine and as an insecticide

WordNet

Nic"o*tine noun
Etymology
F. nicotine. See Nicotian.
Definitions
  1. (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.

Webster 1913