[syn: sinful, unholy, wicked]
The Collaborative International Dictionary of English v.0.48:
unholy \un*ho"ly\ ([u^]n*h[=o]"l[y^]), a.
   Not holy; unhallowed; not consecrated; hence, profane;
   wicked; impious. -- un*ho"li*ly, adv. -- un*ho"li*ness,
   n.
   [1913 Webster]
WordNet (r) 3.0 (2006):
unholy
    adj 1: not hallowed or consecrated [syn: unholy, unhallowed]
           [ant: holy]
    2: extremely evil or cruel; expressive of cruelty or befitting
       hell; "something demonic in him--something that could be
       cruel"; "fires lit up a diabolic scene"; "diabolical
       sorcerers under the influence of devils"; "a fiendish
       despot"; "hellish torture"; "infernal instruments of war";
       "satanic cruelty"; "unholy grimaces" [syn: demonic,
       diabolic, diabolical, fiendish, hellish, infernal,
       satanic, unholy]
    3: having committed unrighteous acts; "a sinful person" [syn:
       sinful, unholy, wicked]
Moby Thesaurus II by Grady Ward, 1.0:
35 Moby Thesaurus words for "unholy":
   amiss, barbarous, blamable, blameful, censurable, culpable,
   fleshly, godless, guilty, impious, irreligious, irreverent,
   mundane, nonsacred, profane, reprehensible, reprobate, secular,
   sinful, temporal, un-Christly, unangelic, unblessed, unchristian,
   uncivilized, unconscionable, ungodly, unhallowed, unregenerate,
   unrighteous, unsacred, unsaintly, unsanctified, wicked, worldly