The Collaborative International Dictionary of English v.0.48:

Dere \Dere\, v. t. [AS. derian to hurt.]
   To hurt; to harm; to injure. [Obs.] --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dere \Dere\, n.
   Harm. [Obs.] --Robert of Brunne.