WordNet (r) 3.0 (2006):

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, iron 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,
       iron oak, Quercus chrysolepis]