To move the drill stem up and down in the hole over a short distance without rotation. careless execution of this operation creates pressure surges that can cause a formation to break down, resulting in lost circulation.
To force a wireline tool or tubing down the hole by using a reciprocating motion.
To begin drilling [...]

To begin drilling; to start the hole.

The fluid used when drilling starts at the surface, often a thick bentonite-lime slurry.