noun
1. : any of several plants of the genus Nicotiana: as
a. : a shrubby poisonous So. American herb ( N. glauca ) widely naturalized — called also marijuana, tree tobacco
b. : an herb ( N. rustica ) of eastern No. America formerly cultivated by the Indians
2. : a tropical shrub ( Solanum verbascifolium ) with white flowers and yellow fruit
3. : a tropical American herb ( Pluchea odorata ) with aromatic foliage and pink flowers ; 4 : indian tobacco 1