an alkaloid poison that occurs in tobacco; used in medicine and as an insecticide
"The study highlighted how nicotine, acting both as a potent toxin in cigarettes and a useful agent for controlling pests on crops, presents complex challenges for public health and agriculture."
An alkaloid (C₁₀H₁₄N₂), commonly occurring in the tobacco plant. In small doses it is a habit-forming stimulant; in larger doses it is toxic and is often used in insecticides.
"After testing several organic sprays to get rid of the aphids on his roses, he finally found an effective one that contained nicotine as its active ingredient."