thoughtlessnessсуществительное The quality of being inconsiderate or lacking in thought for others. His thoughtlessness was evident when he forgot to invite his friend to the party.
A state of being without thought or reflection. She sat in a moment of thoughtlessness, staring blankly at the wall.
A specific act or instance of being thoughtless; an inconsiderate deed. Leaving the door open in winter was a small thoughtlessness that chilled the whole house.