1. 
[syn: underhung, undershot, underslung]
The Collaborative International Dictionary of English v.0.48:
Undershot \Un"der*shot`\, a.
   1. (Zool.) Having the lower incisor teeth projecting beyond
      the upper ones, as in the bulldog.
      [1913 Webster]
   2. Moved by water passing beneath; -- said of a water wheel,
      and opposed to overshot; as, an undershot wheel.
      [1913 Webster]
WordNet (r) 3.0 (2006):
undershot
    adj 1: having a lower part projecting beyond the upper; "an
           underhung jaw"; "undershot bulldog" [syn: underhung,
           undershot, underslung]