orthotomic

Etymology
From.

Adjective

 * 1)  Cutting at right angles.
 * 2)  imaginary; involving the square root of a negative number.

Noun

 * 1)  The line that joins the poles of the common chord on two orthotomic circles.
 * 2)  The envelope of the family of circles that have centers on a specified curve and which pass through a specified point.