Webster’s Revised Unabridged Dictionary · 1913
Pipelayer
Pipe′lay′er (·lā′ẽr), n., or Pipe′ lay′er. 1. One who lays conducting pipes in the ground, as for water, gas, etc.
2. (Polit. Cant) A politician who works in secret; — in this sense, usually written as one word. [U.S.]