secondlongest

Second-longest is a relative descriptor used to identify the item with the second greatest length or extent within a defined set. It presupposes an ordering by a specified measure, and its value can change if the set, units, or inclusion rules change. Because rankings depend on definitions, the second-longest can be affected by ties and measurement methods.

In geography and natural features, second-longest is commonly used for rivers, coastlines, and mountain ranges. For example, in the United States the Missouri River is widely cited as the longest river, while the Mississippi River is commonly cited as the second-longest. Rankings in other countries vary with local data and measurement standards.

In computing and mathematics, second-longest appears in problems about sequences and collections. It may refer to the second-largest numeric value or to the second-longest string by character count. Algorithms to find it typically maintain the largest and the second-largest elements while handling ties.

In everyday use, the term appears in sports, architecture, biology, and linguistics whenever a ranking by length is relevant. It is important to specify the measurement criterion to avoid ambiguity.

See also: longest, ranking, order statistics. References vary by source, reflecting differences in data collection and methodology.