The Collaborative International Dictionary of English v.0.48:

Harefoot \Hare"foot`\ (-f[oo^]t`), n.
   1. (Zool.) A long, narrow foot, carried (that is, produced or
      extending) forward; -- said of dogs.
      [1913 Webster]

   2. (Bot.) A tree (Ochroma Lagopus) of the West Indies,
      having the stamens united somewhat in the form of a hare's
      foot.
      [1913 Webster]

   Harefoot clover (Bot.), a species of clover (Trifolium
      arvense) with soft and silky heads.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Harefoot
    n 1: illegitimate son of Canute who seized the throne of England
         in 1037 (died in 1040) [syn: Harold I, King Harold I,
         Harold Harefoot, Harefoot]