2. Noun. (military) An individual, selected by the column commander, who travels in the lead vehicle or element to regulate the column speed and establish the pace necessary to meet the required movement order'''Joint Publication 1-02 ''U.S. Department of Defense Dictionary of Military and Associated Terms; 12 April 2001 (As Amended Through 14 April 2006).'''''. ¹
¹ Source: wiktionary.com