The Collaborative International Dictionary of English v.0.48:

Unregenerate \Un`re*gen"er*ate\, Unregenerated
\Un`re*gen"er*a`ted\, a.
   Not regenerated; not renewed in heart; remaining or being at
   enmity with God.
   [1913 Webster]

WordNet (r) 3.0 (2006):

unregenerate
    adj 1: tenaciously unwilling or marked by tenacious
           unwillingness to yield [syn: stubborn, obstinate,
           unregenerate] [ant: docile]
    2: not reformed morally or spiritually; "unregenerate human
       nature"; "unregenerate conservatism" [syn: unregenerate,
       unregenerated] [ant: regenerate]
    3: unrepentant and incapable of being reformed; "an unregenerate
       criminal" [syn: unreformable, unregenerate]