† ˈsubsecantMath.Obs.rare. [f. sub- 1 + secant B 2 b.] That part of the axis of abscissas of a curve which is intercepted between a secant and the ordinate. 1816tr.Lacroix' Diff. & Int. Calc. 655 Its subtangent P T must consequently be less than one of the subsecants.