Synonyms and related words :
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