From WordNet (r) 2.0 (August 2003) [wn]:
hibiscus
n : any plant of the genus Hibiscus
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Hibiscus \Hi*bis"cus\, n. [L., marsh mallow; cf. Gr. ?.] (Bot.)
A genus of plants (herbs, shrubs, or trees), some species of
which have large, showy flowers. Some species are cultivated
in India for their fiber, which is used as a substitute for
hemp. See Althea, Hollyhock, and Manoe.
[1913 Webster]