Vigilance

Proper attention in proper time.

The law requires a man who has a claim to enforce it in proper time, while the adverse party has it in his power to defend himself; and if by his neglect to do so, he cannot afterwards establish such claim, the maxim vigilantibus non dormientibus leges subserviunt, acquires full force in such case. For example, a claim not sued for within the time required by the acts of limitation, will be presumed to be paid; and the mere possession of corporeal real property, as if in fee simple, and without admitting any other ownership for sixty years, is a sufficient title against all the world, and cannot be impeached by any dormant claim.
   

This entry contains material from Bouvier's Legal Dictionary, a work published in the 1850's.