WordNet (r) 3.0 (2006):

Maclura pomifera
    n 1: small shrubby deciduous yellowwood tree of south central
         United States having spines, glossy dark green leaves and
         an inedible fruit that resembles an orange; its hard
         orange-colored wood used for bows by Native Americans;
         frequently planted as boundary hedge [syn: osage orange,
         bow wood, mock orange, Maclura pomifera]