1.NounA machine for forcing a pile, a long beam, into the ground as part of the construction of a foundation; usually by raising a weight and then dropping it on the beam.
2.NounA person or thing who hits or attacks forcefully or powerfully.
"She scored a goal with a pile driver from the edge of the penalty box"
3.AdjectiveForceful.
"The champ ended the boxing match with a pile driver blow to his opponent’s jaw."