incautious

Synonyms: any old way bold brash careless caught napping devilmay-care fast-and-loose foot-in-mouth hasty heedless hotheaded ill-advised illjudged impetuous improvident imprudent impulsive inconsiderate indiscreet injudicious madcap neglectful negligent off guard pay no mind playing with fire precipitate rash reckless regardless sticking one’s neck out thoughtless unalert unguarded unmindful unthinking unvigilant unwatchful wary wide open

Antonyms: careful cautious discreet thoughtful