radius vector

American  

noun

plural

radii vectores, radius vectors

1. Mathematics. the length of the line segment joining a fixed point or origin to a given point.

2. Astronomy.

   1. the straight line joining two bodies in relative orbital motion, as the line from the sun to a planet at any point in its orbit.

   2. the distance between two such bodies at any point in the orbit.

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radius vector British  

noun

1. maths a line joining a point in space to the origin of polar or spherical coordinates

2. astronomy an imaginary line joining a satellite to the planet or star around which it is orbiting

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radius vector Scientific  

1. A line segment that joins the origin and a variable point in a system of polar or spherical coordinates.

2. The imaginary straight line that connects the center of the Sun or another body with the center of a planet, comet, or other body that orbits it.

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Etymology

Origin of radius vector

First recorded in 1745–55