iron oak n 1: small deciduous tree of eastern and central United States having dark green lyrate pinnatifid leaves and tough moisture-resistant wood used especially for fence posts [syn: {post oak}, {box white oak}, {brash oak}, {Quercus stellata}] 2: medium-sized evergreen of southwestern United States and northwestern Mexico with oblong leathery often spiny-edged leaves [syn: {canyon oak}, {canyon live oak}, {maul oak}, {Quercus chrysolepis}]