Hel″i‐coid (?), a. [Gr. �; ἕλιξ, -ικοσ, spiral + � shape: cf. F. hélicoïde. See Helix.]
1. Spiral; curved, like the spire of a univalve shell.
2. (Zoöl.) Shaped like a snail shell; pertaining to the Helicidæ, or Snail family.
Helicoid parabola(Math.), the parabolic spiral.