**Di*rect"rix** (?), n.; pl. E. Directrixes (), L. Directrices ().

**1.**

A directress.

[R.]

*Jer. Taylor.*

**2.** Geom. (a)

A line along which a point in another line moves, or which in any way governs the motion of the point and determines the position of the curve generated by it; the line along which the generatrix moves in generating a surface.

(b)

A straight line so situated with respect to a conic section that the distance of any point of the curve from it has a constant ratio to the distance of the same point from the focus.

© Webster 1913.