2 entries under this word
n. [Fr. hélicoïde, Gr. ἑλικοειδής; ἕλιξ, spiral, and εἶδος, shape. See HELIX.] (Geom.) A warped surface which may be generated by a straight line moving in such a manner that every point of it shall have a uniform motion in the direction of a fixed straight line, and at the same time a uniform angular motion about it. Math. Dict.
a. Spiral; spirally curved, like the spire of a univalve shell.
Helicoid parabola (Math.), the curve which would be formed, upon the supposition that the axis of the common parabola is bent round into the periphery of a circle, by a line passing through the extremities of the ordinates, which now converge toward the center of the said circle; —called also the parabolic spiral.