The Collaborative International Dictionary of English v.0.48:

honky \honky\ n.
   1. A white (caucasian) person; -- a term used by some
      African-Americans, intended to be disparaging and often
      taken as offensive. [Also spelled honkie and honkey.]

   Syn: whitey.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

honkey
    n 1: (slang) offensive names for a White man [syn: whitey,
         honky, honkey, honkie]