he·li·coid /ˈhɛləˌkɔɪd, ˈhi-/
  (a.)螺旋狀的,蝸牛殼狀的,迴轉式的螺旋體,螺旋面
  he·li·coid /ˌhɛləˈkɔɪdḷ, ˌhɪlə-/ 形容詞
  helicoid
  螺旋面
  Hel·i·coid a.
  1. Spiral; curved, like the spire of a univalve shell.
  2. Zool. Shaped like a snail shell; pertaining to the Helicidae, or Snail family.
  Helicoid parabola Math., the parabolic spiral.
  Hel·i·coid, n. Geom. 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.
  ◄ ►