Careful. Also heedful or diligent.
careful
The opposite of cautious is: Careless or Hasty
careless parents
careless, uncaring
careless
Careful.
it means careless
The opposite of drive safe is careless driving.
careful
careful; responsible
Not caring, uncaring, careless
Inaccurate, careless, wrong, faulty.
The opposite word of responsible is irresponsible.