WordNet (r) 3.0 (2006):

English hawthorn
    n 1: European hawthorn having deeply cleft leaves and bright red
         fruits; widely cultivated in many varieties and often grown
         as impenetrable hedges; established as an escape in eastern
         North America [syn: English hawthorn, Crataegus
         monogyna]
    2: thorny Eurasian shrub of small tree having dense clusters of
       white to scarlet flowers followed by deep red berries;
       established as an escape in eastern North America [syn:
       whitethorn, English hawthorn, may, Crataegus
       laevigata, Crataegus oxycantha]