The Collaborative International Dictionary of English v.0.48:
Hawthorn \Haw"thorn`\ (h[add]"th[^o]rn`), n. [AS.
haga[thorn]orn, h[ae]g[thorn]orn. See Haw a hedge, and
Thorn.] (Bot.)
A thorny shrub or tree (the Crat[ae]gus oxyacantha), having
deeply lobed, shining leaves, small, roselike, fragrant
flowers, and a fruit called haw. It is much used in Europe
for hedges, and for standards in gardens. The American
hawthorn is Crat[ae]gus cordata, which has the leaves but
little lobed.
[1913 Webster]
Gives not the hawthorn bush a sweeter shade
To shepherds? --Shak.
[1913 Webster]