celtis occidentalis

from WordNet (r) 3.0 (2006)

Celtis occidentalis
    n 1: large deciduous shade tree of southern United States with
         small deep purple berries [syn: {American hackberry},
         {Celtis occidentalis}]

from The Collaborative International Dictionary of English v.0.48

Hackberry \Hack"ber`ry\ (h[a^]k"b[e^]r`r[y^]), n. (Bot.)
   A genus of trees ({Celtis}) related to the elm, but bearing
   drupes with scanty, but often edible, pulp. {Celtis
   occidentalis} is common in the Eastern United States. --Gray.
   [1913 Webster]