The Collaborative International Dictionary
Regression point
Regression \Re*gres"sion\ (r?*gr?sh"?n), n. [L. regressio: cf.
F. r['e]gression.]
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.