The Collaborative International Dictionary of English v.0.48:

Unadvised \Un`ad*vised"\, a.
   1. Not prudent; not discreet; ill advised. --Shak.
      [1913 Webster]

   2. Done without due consideration; wanton; rash;
      inconsiderate; as, an unadvised proceeding.
      [1913 Webster] -- Un`ad*vis"ed*ly, adv. --
      Un`ad*vis"ed*ness, n.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unadvised
    adj 1: without careful prior deliberation or counsel; "ill-
           advised efforts"; "it would be ill-advised to accept the
           offer"; "took the unadvised measure of going public with
           the accusations" [syn: ill-advised, unadvised] [ant:
           advised, well-advised]
    2: having received no information; "a defendant unadvised of her
       legal rights"

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "unadvised":
   automatic, brash, casual, gut, hasty, hotheaded, ill-advised,
   ill-considered, ill-contrived, ill-devised, ill-gauged, ill-judged,
   impolitic, imprudent, inadvertent, inadvisable, inconsiderate,
   indeliberate, indiscreet, inexpectant, inexpedient, injudicious,
   insensate, involuntary, irrational, mindless, misadvised,
   misguided, myopic, nonexpectant, reasonless, reckless, reflex,
   reflexive, senseless, shortsighted, snap, spontaneous, thoughtless,
   unadmonished, unanticipating, unanticipative, unaware,
   uncalculated, unconscious, unconsidered, undeliberate,
   undeliberated, undesigned, undiscerning, unexpecting, unforeseeing,
   unforewarned, unguessing, uninformed, unintended, unintentional,
   unmeditated, unpremeditated, unprepared, unready, unreasonable,
   unreflecting, unreflective, unseeing, unsensible, unsound,
   unstudied, unsuspecting, unthinking, unthoughtful, unwarned,
   unwilled, unwise, witless