Meaning of helicoid

hel•i•coid

Pronunciation: (hel'i-koid", hē'li-), [key]
— adj.
  1. coiled or curving like a spiral.
—n.
  1. a warped surface generated by a straight line moving so as to cut or touch a fixed helix.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.