REGRESSION

Re‐gres″sion (r?‐gr?sh″?n), n. [[L. regressio: cf. F. régression.]] The act of passing back or returning; retrogression; retrogradation. Sir T. Browne. Edge of regression (of a surface) (Geom.), the line along which a surface turns back upon itself; — called also a cuspidal edge. — Regression point (Geom.), a cusp.