Paraboloid \Pa*rab"o*loid\ (-loid), n. [Parabola + -oid: cf. F. parabolo["i]de.]

(Geom.) The solid generated by the rotation of a parabola about its axis; any surface of the second order whose sections by planes parallel to a given line are parabolas. [1913 Webster]

Note: The term paraboloid has sometimes been applied also to the parabolas of the higher orders. --Hutton. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

Conoid \Co"noid\ (k[=o]"noid), n. [Gr. kwnoeidh`s conical; kw^nos cone + e'i^dos form: cf. F. cono["i]de.]

1. Anything that has a form resembling that of a cone. [1913 Webster]

2. (Geom.)
   (a) A solid formed by the revolution of a conic section about its axis; as, a parabolic conoid, elliptic conoid, etc.; -- more commonly called paraboloid, ellipsoid, etc.
   (b) A surface which may be generated by a straight line moving in such a manner as always to meet a given straight line and a given curve, and continue parallel to a given plane. --Math. Dict. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

paraboloid

Source: WordNet (r) 2.0
 

Paraboloid \Pa*rab"o*loid\ (-loid), n. [Parabola + -oid: cf. F. parabolo["i]de.]

(Geom.) The solid generated by the rotation of a parabola about its axis; any surface of the second order whose sections by planes parallel to a given line are parabolas.

Note: The term paraboloid has sometimes been applied also to the parabolas of the higher orders. --Hutton.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Conoid \Co"noid\, n. [Gr. ? conical; ? cone + ? from: cf. F. cono["i]de.]

1. Anything that has a form resembling that of a cone.

2. (Geom.)
   (a) A solid formed by the revolution of a conic section about its axis; as, a parabolic conoid, elliptic conoid, etc.; -- more commonly called paraboloid, ellipsoid, etc.
   (b) A surface which may be generated by a straight line moving in such a manner as always to meet a given straight line and a given curve, and continue parallel to a given plane. --Math. Dict.

Source: Webster's Revised Unabridged Dictionary (1913)