The Collaborative International Dictionary of English v.0.48:

Dearn \Dearn\, a. [AS. derne, dyrne, dierne, hidden, secret. Cf.
   Derne.]
   Secret; lonely; solitary; dreadful. [Obs.] --Shak. --
   Dearn"ly, adv. [Obs.] --Chaucer.
   [1913 Webster]