| Noun | 1. | hawthorn - a spring-flowering shrub or small tree of the genus CrataegusCrataegus biltmoreana, scarlet haw - common shrub or small tree of the eastern United States having few thorns and white flowers in corymbs followed by bright orange-red berries Crataegus monogyna, English hawthorn - 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 bush, shrub - a low woody perennial plant usually having several major branches | |