conjugate axis

noun

Geometry.

1. the axis of a hyperbola perpendicular to the transverse axis at a point equidistant from the foci.

2. the segment of this axis equal to one side of a rectangle that has its other side equal to the transverse axis and diagonals that are along the asymptotes of the hyperbola.

Word History and Origins

Origin of conjugate axis¹

First recorded in 1875–80