regression (ss as sh)

[Lat. regre io, from regre us, pa. par. of regredior.] [REGRESS, 8.] The act of pa ing back or returning; retrogre ion. "Restrains from regre ion into nothing."--Browne: Vulgar Errors , bk. i., ch. ix. Regre ion of the moon's nodes : Astron.: The motion backward of the moon's nodes. It averages 19° 19′ 42-316" a year, and the node makes a complete retrograde revolution in 6793-39108 solar days, or nearly 18-6 years. regre ion-point, s. Geom.: A point at which two branches are tangent to each other, so that a point generating the curve suddenly stops at the cusp, and returns for a time in the same general direction from which it arrived at the cusp point.