Definition of the word fall in

The expression "fall in" is a military term that originated in the 19th century. It's a command given by a senior officer to a group of soldiers, directing them to assemble in a specific location for an inspection, roll call, or other gatherings. The origin of the term "fall in" is debated, but one theory suggests that it comes from the action of soldiers falling into their designated positions in formation. This falls in line with the military's adherence to strict discipline and structure, where each soldier must know their position and be ready for orders. An alternate theory suggests that "fall in" derives from an older practice, when commanders would signal their location by dropping their hat or throwing it to the ground. In this interpretation, "fall in" means to gather around the commander's location, as the location was signaled by the dropped or thrown hat. Regardless of the exact origin, "fall in" is still commonly used in the military today and is recognized as a symbol of military precision, discipline, and honor.