headlong
Definitions
With the head foremost.
In a rush; with uncontrolled speed or recklessness.
Examples
He dived headlong into the swimming pool to escape the summer heat.
The company rushed headlong into the new market without conducting any proper research.
She fell headlong down the stairs but fortunately escaped with only minor bruises.
Synonyms
precipitate hasty impulsive reckless rushed impetuous hurried