thoughtless

showing lack of careful thought

• “the debate turned into thoughtless bickering”

marked by or paying little heed or attention

• “We have always known that heedless self-interest was bad morals; we know now that it is bad economics” -Franklin D. Roosevelt
• “heedless of danger”
• “heedless of the child”

without care or thought for others

• “the thoughtless saying of a great princess on being informed that the people had no bread;”
• “'”

(usually followed by `of'') without due thought or consideration

• “careless of the consequences”
• “the proverbial grasshopper--thoughtless of tomorrow”
• “crushing the blooms with regardless tread”