ironwood tree 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}, {Mesua ferrea}] 2: a small slow-growing deciduous tree of northern Iran having a low domed shape [syn: {iron tree}, {iron-tree}, {ironwood}] 3: medium-sized hop hornbeam of eastern North America [syn: {Eastern hop hornbeam}, {ironwood}, {Ostrya virginiana}]