axis of symmetry

noun

1. Mathematics. a straight line for which every point on a given curve has corresponding to it another point such that the line connecting the two points is bisected by the given line.
2. Crystallography. rotation axis.

Word History and Origins

Origin of axis of symmetry¹

First recorded in 1875–80

Example Sentences

This wobble in Earth’s rotation occurs because the axis around which our planet rotates doesn’t quite line up with its actual geometric axis of symmetry, causing the rotational axis to keep trying to adjust.

From Scientific American

Where a changes the width of the curve, b shifts the axis of symmetry to the left or right, and c slides the curve up or down.

From Seattle Times

The midpoint, or average, of r and s is the axis of symmetry of the parabola.

From Seattle Times

The two solutions to the quadratic equation will be the axis of symmetry plus or minus an unknown amount, which we’ll call u.

From Seattle Times

For a binary pair to produce that shape, the nebula’s long axis of symmetry should point in the same direction as the axis around which the stars orbit.

From Science Magazine