Laches in Harpers Dictionary of Classical Antiquities (1898)
An Athenian general who fell at the battle of Mantinea, B.C. 418. A dialogue of Plato bears his name. See Plato.
Laches in Wikipedia
Laches (pronounced /ˈlætʃɨz/) (f. French, lâchesse, lâches)  is an equitable defense, or doctrine. The person invoking laches is asserting that an opposing party has "slept on its rights," and that, as a result of this delay, that other party is no longer entitled to its original claim. Put another way, failure to assert one’s rights in a timely manner can result in a claim's being barred by laches. Laches is a form of estoppel for delay. In Latin,
Vigilantibus non dormientibus æquitas subvenit.
Equity aids the vigilant, not the sleeping ones (that is, those who sleep on their rights).
In most contexts, an essential element of laches is the requirement that the party invoking the doctrine has changed its position as a result of the delay. In other words, the defendant is in a worse position now than at the time the claim should have been brought. For example, the delay in asserting the claim may have caused a great increase in the potential damages to be awarded, or assets that could earlier have been used to satisfy the claim may have been distributed in the meantime, or the property in question may already have been sold, or evidence or testimony may no longer be available to defend against the claim.
A defense lawyer raising the defense of laches against a motion for injunctive relief (a form of equitable relief) might argue that the plaintiff comes "waltzing in at the eleventh hour" when it is now too late to grant the relief sought, at least not without causing great harm that the plaintiff could have avoided. In certain types of cases (for example, cases involving time-sensitive matters, such as elections), a delay of even a few days is likely to be met with a defense of laches, even where the applicable statute of limitations might allow the type of action to be commenced within a much longer time period.
A successful defense of laches will find the court denying the request for equitable relief. However, even if equitable relief is not available, the party may still have an action at law if the statute of limitations has not run out.
Under the United States Federal Rules of Civil Procedure, laches is an affirmative defense, which means that the burden of asserting laches is on the party responding to the claim to which it applies. "When the defense of laches is clear on the face of the complaint, and where it is clear that the plaintiff can prove no set of facts to avoid the insuperable bar, a court may consider the defense on a motion to dismiss." Solow v. Nine West Group, 2001 WL 736794, *3 (S.D.N.Y. June 29, 2001); Simons v. United States, 452 F.2d 1110, 1116 (2d Cir. 1971) (affirming Rule 12(b)(6) dismissal based, in part, on laches where papers "reveal no reason for the inordinate and prejudicial delay")
Compared to statute of limitations
The defense of laches resembles, but is not entirely analogous to, a plea that the period of time allowed under a statute of limitations has expired. Laches essentially alleges prejudicial delay and unfairness in the context of a particular situation, whereas statutes of limitation tend to define a specific legally prescribed period of time (after the cause of action has accrued) within which a lawsuit for a particular type of cause of action may be commenced or after which the right to recovery is barred. Moreover, although a lawsuit commenced within the time allowed by a limitations period is valid no matter how long it takes for the action to proceed to trial, laches can sometimes be applied even in a situation where a lawsuit has been commenced and any delays would otherwise be reasonable. It is generally allowed by a court when a defendant could reasonably have believed that the plaintiff was not going to exercise his or her legal rights and acted on that belief to his or her detriment.
Laches (Gr. Λάχης) (c.475 BC - 418 BC) was an Athenian aristocrat (son of Melanopos) and general during the Peloponnesian War. His date of birth is unknown, but Plato asserts, not implausibly, that he was distinctly older than Socrates, who was born around 470 BC.
In 427 BCE, Laches and Charoeades were sent to Sicily with a fleet of 20 ships in order to support Athenian allies against Syracuse. When Charoeades died in 426 BCE, Laches took over the supreme command of the fleet and forced the cities of Mylae and Messana to yield. However, due to the annual reappointment of generals, at the beginning of 425 BCE he was replaced by Pythodoros as supreme commander. The first Athenian expedition to Sicily ended badly. Upon Laches return to Athens he was prosecuted by Cleon, but was acquitted of any wrong-doing. His trial was satirized by Aristophanes in his play The Wasps.
In 423 BCE, Laches successfully moved for an armistice with Sparta in the Athenian Assembly. However, it only lasted a year. But after Cleon died in 422 BCE, Laches, together with Nicias, was able to negotiate a slightly longer peace, the Peace of Nicias. In 418 BCE the peace broke down because of Athens’s support for Spartan rebels. Laches was again appointed general and was killed in the Athenian’s disastrous defeat at the Battle of Mantinea.
The Platonic dialogue Laches features Laches as a stereotypical conservative general.
Laches was a quite common name at Athens; the archon of 400/399 BC, the year of Socrates' execution, was another Laches. Kirchner's Prosopographia Attica lists eighteen men of the name of Laches, including the general's son, grandson, and great-grandson, who appear in Demosthenes' speech against Timocrates ( Demosthenes 24) and in his letters. There was also another Laches, son of Demochares, who was Demosthenes' cousin and brother-in-law, but he was of another deme and family. There was also a captain at the battle of Coronea (394 BC); and an Athenian commander who fought (and lost to) Epaminondas in 364 BC.
The Laches (Greek: Λάχης) is a Socratic dialogue written by Plato. Participants in the discourse present competing definitions of the concept of courage.
The Laches were an indigenous, agrarian people in the highlands of what is now central Colombia's northern Boyacá and Santander departments. They were part of the Cocuy Confederation and spoke a Chibchan language, trading predominantly with other Chibchan speakers, such as the Muiscas, Guanes, Pijaos and Chitareros. They farmed maize, potato, quinoa and cotton, among other crops.
In the 17th century, Lucas Fernández de Piedrahita wrote of the habit of the Laches in bringing up younger male children as culturally female, that is, as berdaches. 
The name Laches is preserved in a suburb, or barrio, of Bogotá known as Los Laches.