trochoid

American  

[troh-koid] / ˈtroʊ kɔɪd /

noun

1. Geometry. a curve traced by a point on a radius or an extension of the radius of a circle that rolls, without slipping, on a curve, another circle, or a straight line. Equation: x = aθ − b sin θ, y = a − b cos θ.

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adjective

1. rotating on an axis, as a wheel.

trochoid British  

/ ˈtrəʊkɔɪd /

noun

1. the curve described by a fixed point on the radius or extended radius of a circle as the circle rolls along a straight line

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adjective

1. rotating or capable of rotating about a central axis

2. anatomy (of a structure or part) resembling or functioning as a pivot or pulley

Other Word Forms

• trochoidal adjective
• trochoidally adverb

Etymology

Origin of trochoid

First recorded in 1695–1705, trochoid is from the Greek word trochoeidḗs round like a wheel. See troche, -oid

Example Sentences

Globigerinidaceae.—Shells vitreous, coarsely perforated; chambers few spheroidal rapidly increasing in size; arranged in a trochoid or nautiloid spiral.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 6 "Foraminifera" to "Fox, Edward" by Various

X. Rotalidaceae.—Shells vitreous, finely perforate; walls thick, often double, but without an intermediate party-layer traversed by canals; form usually spiral or trochoid.

From Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 6 "Foraminifera" to "Fox, Edward" by Various