1. Any of various plants of the genus Nicotiana, especially N. tabacum, native to tropical America and widely cultivated for their leaves, which are used primarily for smoking.
2. The leaves of these plants, dried and processed chiefly for use in cigarettes, cigars, or snuff or for smoking in pipes.
3. Products made from these plants.
4. The habit of smoking tobacco: I gave up tobacco.
5. A crop of tobacco.

[Spanish tabaco, possibly of Caribbean origin.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.