iron·wood /-ˌwʊd/
 硬木
 I·ron·wood n. Bot. A tree unusually hard, strong, or heavy wood.
 Note: ☞ In the United States, the hornbeam and the hop hornbeam are so called; also the Olneya Tesota, a small tree of Arizona; in the West Indies, the Erythroxylon areolatum, and several other unrelated trees; in China, the Metrosideros vera; in India, the Mesua ferrea, and two species of Inga; in Australia, the Eucalyptus Sideroxylon, and in many countries, species of Sideroxylon and Diospyros, and many other trees.
 ◄ ►
 ironwood
      n 1: handsome East Indian evergreen tree often planted as an
           ornamental for its fragrant white flowers that yield a
           perfume; source of very heavy hardwood used for railroad
           ties [syn: rose chestnut, ironwood tree, Mesua
           ferrea]
      2: exceptionally tough or hard wood of any of a number of
         ironwood trees
      3: a small slow-growing deciduous tree of northern Iran having
         a low domed shape [syn: iron tree, iron-tree, ironwood
         tree]
      4: medium-sized hop hornbeam of eastern North America [syn: Eastern
         hop hornbeam, ironwood tree, Ostrya virginiana]