Tobacco is a product prepared from the leaves of the tobacco plant by curing them. The plant is part of the genus Nicotiana and of the Solanaceae (nightshade) family. While more than 70 species of tobacco are known, the chief commercial crop is N. tabacum. The more potent variant N. rustica is also used around the world.
Tobacco contains the alkaloid nicotine, which is a stimulant. Dried tobacco leaves are mainly used for smoking in cigarettes, cigars, pipe tobacco, and flavored shisha tobacco. They can be also consumed as snuff, chewing tobacco, dipping tobacco and snus.
Tobacco use is a risk factor for many diseases, especially those affecting the heart, liver, and lungs, as well as many cancers. In 2008, the World Health Organization named tobacco as the world's single greatest cause of preventable death.
The English word "tobacco" originates from the Spanish and Portuguese word "tabaco". The precise origin of this word is disputed, but it is generally thought to have derived at least in part, from Taino, the Arawakan language of the Caribbean. In Taino, it was said to mean either a roll of tobacco leaves (according to Bartolomé de las Casas, 1552), or to tabago, a kind of Y-shaped pipe used for sniffing tobacco smoke (according to Oviedo; with the leaves themselves being referred to as cohiba).