Something that constrains; a restriction.
An irresistible force or compulsion.
A condition that a solution to an optimization problem must satisfy.
A linkage or other restriction that maintains database integrity.
The repression of one's feelings.
The act of preventing or hindering; obstruction of action, access, or approach; thwarting.
precaution; forethought.
Any measure intended to limit health-related risks (such as information campaigns, vaccination, early diagnosis etc.).