P / post-signāni
noun

post-signāni

gen. ōrum · gender masculine · decl. 2nd
(sc. milites) [signum]
the soldiers who are stationed behind the standards
the soldiers who are stationed behind the standards (opp. antesignani), Front. Strat. 2, 3, 17; Amm. 18, 8, 7; 24, 6, 9.