Constrained optimum
The solution of a constrained optimization problblem at which one or more constraints are hinding. Also referred to as constrained maximiini (minimum) when optimization involves maximizing (minimizing) the objective function.
The optimum is constrained if, at the saddle point, at least one of the constraints holds as an equality. Examples of constrained optima are the maximization of utility subject to a budget constraint for a consumer who is never satiated, and the minimization o cost subject to a production constraint for a firm employing factors of production with strictly positive prices.
Reference: Oxford Press Dictonary of Economics, 5th edt.