Helicoid

Part of speech: noun (n.)

A warped surface which may be generated by a straight line moving in such a manner that every point of the line shall have a uniform motion in the direction of another fixed straight line, and at the same time a uniform angular motion about it.

Part of speech: adjective (a.)

1. Spiral; curved, like the spire of a univalve shell.

2. Shaped like a snail shell; pertaining to the Helicidæ, or Snail family. Helicoid parabola (Math.), the parabolic spiral.