Definition of sub

The word "sub" is a common shortening of the term "submarine," which originally derived from the Latin word "submarium," meaning "lying below." During the late 19th century, as submarine technology was still in development, the word "submarine" was used to describe any type of vessel that could navigate below the surface of the water. In time, as submarines became more advanced and sophisticated, the term "submarine" became specific to these underwater vessels designed for military use. The use of "sub" as a shortened version of "submarine" began to emerge during the first half of the 20th century, particularly in naval and military contexts. Overall, the word "sub" has come to be commonly used by individuals from various backgrounds, including sailors, military personnel, and enthusiasts of submarine culture, as a shorthand word to describe submarines or submarine-related activities. Its origins in Latin and the history of submarine technology have given it a rich, multifaceted backstory that continues to be a part of its contemporary use.