A doctrine from the law of equity holding that a party that unjustifiably delays acting on a right for an excessive period of time can lose the opportunity to go forward at a later date. Laches can be asserted even if a contractual time bar was not invoked in the past. It operates on the basis that witnesses with a clear recollection of the facts and pertinent evidence may no longer be available because of the delay in proceeding with a cause of action.