She listened heedfully to his advice.

He was heedy of his surroundings.

She was always heedfull of her surroundings.

She listened heedily to his instructions.

She heedeth the advice of her elders.

Thou heedest my advice.

The heedlessnesses of the students led to poor academic performance.

The heeders gathered to discuss the latest developments.

She is a diligent heeder and always listens attentively in class.

Her heediness was evident in the way she carefully considered every decision.