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]

WordNet (r) 3.0 (2006):

hawthorn
    n 1: a spring-flowering shrub or small tree of the genus
         Crataegus [syn: hawthorn, haw]

U.S. Gazetteer Places (2000):

Hawthorn, PA -- U.S. borough in Pennsylvania
   Population (2000):    587
   Housing Units (2000): 220
   Land area (2000):     1.107734 sq. miles (2.869019 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    1.107734 sq. miles (2.869019 sq. km)
   FIPS code:            33216
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             41.020621 N, 79.274163 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Hawthorn, PA
    Hawthorn