The designation applied to a specific type of shirt stems primarily from its shape. When laid flat, the garment resembles the capital letter “T,” thus providing a simple, descriptive label. This visual characteristic is the fundamental reason behind its established name.
The widespread adoption of this nomenclature reflects both its intuitive clarity and the garment’s functional design. Its ease of manufacture, comfortable wear, and suitability for various activities contributed to its increasing popularity in the late 19th and early 20th centuries. The U.S. Navy played a significant role in popularizing the shirt as standard undershirts, further solidifying its place in common usage and contributing to the eventual widespread acceptance of the descriptive term based on its distinctive shape.