What is the definition of "laches"?

Laches is a legal term that refers specifically to an unreasonable delay in pursuing a right or claim, resulting in a disadvantage to another party. The correct choice, which focuses on omissions, neglect, or failure to perform a duty, captures the essence of laches. This concept often applies in equitable law, where a party may lose the right to enforce a claim because they waited too long to act, suggesting a neglect of their duty to pursue the claim in a timely manner. The delay must be shown to have prejudiced the other party, making the notion of failure to perform a duty central to the definition.

In contrast, the other options do not adequately encapsulate the nuances of laches. While "within the power" and "he swears" are unrelated terms in this context, "failure to perform a duty" lacks the specific reference to the neglect or omission aspect that is critical to understanding laches. Therefore, the option reflecting omissions and neglect most accurately conveys the legal principle associated with laches.