'cuspidal edge' definitions:

Definition of 'cuspidal edge'

From: GCIDE
  • 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. [1913 Webster]
  • 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. [1913 Webster]