Hypertext Webster Gateway: "Helicoid"
From Webster's Revised Unabridged Dictionary (1913) (web1913)
Helicoid \Hel"i*coid\, a. [Gr. ?; "e`lix, -ikos, spiral + ?
shape: cf. F. h['e]lico["i]de. See {Helix}.]
1. Spiral; curved, like the spire of a univalve shell.
2. (Zo["o]l.) Shaped like a snail shell; pertaining to the
{Helicid[ae]}, or Snail family.
{Helicoid parabola} (Math.), the parabolic spiral.
From Webster's Revised Unabridged Dictionary (1913) (web1913)
Helicoid \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.
Additional Hypertext Webster Gateway Lookup
Gateway by dict@stokkie.net
stock only wrote the gateway and does not have any control over the contents;
see the Webster Gateway FAQ,
and also the Back-end/database links and credits.