Lewis Short
circum-grĕdĭor, gressus, grĕdi
* V dep [gradior], to go or walk around, travel about (esp. in a hostile manner; post-Aug., several times in Tac, elsewhere rare).
* Absol., Tac. A. 1, 64; 2, 17; 12, 28.
* With acc.: exercitum, * Sall. H. 4, 61, 21 Dietsch: terga,Tac. A. 2, 25' Syriam, Aur Vict. Caes. 21' lacunam, Amm. 16, 12, 59.
Charlton T. Lewis, Charles Short, A Latin Dictionary