From WordNet (r) 2.0 (August 2003) [wn]:
Hamamelis
n : deciduous shrubs or small trees: witch hazel [syn:
Hamamelis, genus Hamamelis]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Hamamelis \Ham`a*me"lis\ (h[a^]m`[.a]*m[=e]"l[i^]s), n. [NL.,
fr. Gr. "amamhli`s a kind of medlar or service tree; "a`ma at
the same time + mh^lon an apple, any tree fruit.] (Bot.)
A genus of plants which includes the witch-hazel ({Hamamelis
Virginica}), a preparation of which is used medicinally.
[1913 Webster]