WordNet (r) 3.0 (2006):

ill-advised
    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]

Moby Thesaurus II by Grady Ward, 1.0:

146 Moby Thesaurus words for "ill-advised":
   a bit previous, advanced, automatic, bad, botched, brash, bungled,
   butchered, casual, far ahead, forward, fumbled, futile, gut,
   half-baked, half-cocked, hasty, hotheaded, ill-considered,
   ill-contrived, ill-devised, ill-done, ill-executed, ill-gauged,
   ill-judged, ill-managed, ill-seasoned, ill-suited, ill-timed,
   impolitic, improper, imprudent, impulsive, inadvertent,
   inadvisable, inappropriate, inapt, inauspicious, incautious,
   incongruous, inconsiderate, inconvenient, indeliberate, indiscreet,
   inept, inexpedient, infelicitous, injudicious, inopportune,
   insensate, intempestive, intrusive, involuntary, irrational,
   irrelevant, late, madcap, mal a propos, malapropos, mindless,
   misadvised, misconducted, misdirected, misguided, mismanaged,
   mistimed, muffed, murdered, myopic, negligent, not firm, off base,
   out of line, out of phase, out of place, out of time, overhasty,
   oversoon, precipitate, precocious, premature, previous, rash,
   reasonless, reckless, reflex, reflexive, rushed, senseless,
   shortsighted, snap, spoiled, spontaneous, thoughtless, too early,
   too late, too soon, unadvised, unbefitting, uncalculated,
   unconscious, unconsidered, uncrystallized, undeliberate,
   undeliberated, undesigned, undesirable, undiscerning, unfavorable,
   unfit, unfitting, unforeseeing, unfortunate, unhandy, unhappy,
   unintended, unintentional, unjelled, unlucky, unmatured,
   unmeditated, unmeet, unpremeditated, unprepared, unprofitable,
   unpropitious, unready, unreasonable, unreflecting, unreflective,
   unripe, unseasonable, unseeing, unseemly, unsensible, unsound,
   unstudied, unsuitable, unthinking, unthoughtful, untimely,
   untoward, unwilled, unwise, witless, wrong