Lewis Short
antĕ-signānus (noun M) : signum
* That is before the standard; hence
* Lit.: antesignant (sc. milites),a chosen band of Roman soldiers who fought before the standards, and served for their defence,Caes. B. C. 1, 43; 1, 57; Liv. 22, 5; 9, 39; Varr. ap. Non. p. 553, 10.
* Transf., a leader, commander: in acie Pharsalicā,Cic. Phil. 2, 29; so App. M. 4, p. 147, 12.
Charlton T. Lewis, Charles Short, A Latin Dictionary