Defn: To call, convey orders, etc., by means of signals on a pipe or whistle carried by a boatswain.

3. To emit or have a shrill sound like that of a pipe; to whistle. "Oft in the piping shrouds." Wordsworth.

4. (Metal.)

Defn: To become hollow in the process of solodifying; — said of an ingot, as of steel.

PIPE
Pipe, v. t. [imp. & p. p. Piped; p. pr. & vb. n. Piping.]

1. To perform, as a tune, by playing on a pipe, flute, fife, etc.; to utter in the shrill tone of a pipe. A robin . . . was piping a few querulous notes. W. Irving.

2. (Naut.)

Defn: To call or direct, as a crew, by the boatswain's whistle.
As fine a ship's company as was ever piped aloft. Marryat.

3. To furnish or equip with pipes; as, to pipe an engine, or a building.

PIPE CLAY
Pipe" clay` (