constraint, restraint (noun)
the state of being physically constrained
"dogs should be kept under restraint"
restraint, constraint (noun)
a device that retards something's motion
"the car did not have proper restraints fitted"
the act of constraining; the threat or use of force to control the thoughts or behavior of others
Something that constrains.
A condition that a solution to an optimization problem must satisfy.
In mathematics, a constraint is a condition that a solution to an optimization problem is required by the problem itself to satisfy. There are two types of constraints: equality constraints and inequality constraints. The set of candidate solutions that satisfy all constraints is called the feasible set.