main defensive line, a palisade, a wall of wooden stakes, used as a barrier constructed along an earthwork, together with a tower (1) – (3) and (6)
trenches and obstacles / anti-cavalry devices
The image details a series of ditches (5, 7), forked stakes and spikes (4, 8, 10) and hidden pits (9) designed to impede enemy advances
(1) lōrīca, -ae [1/f]: [i] (soldier’s armour) coat of mail; cuirass [ii] (here) any form of defence e.g. parapet; breastwork i.e. a military fortification consisting of a low wall, often with wooden or wicker defenses
(2) pinnae, -ārum [1/f/pl]: battlements i.e the raised parts behind which defenders could shelter
(3)
agger, -is [3/m]: earthwork, especially defensive ramparts, dykes, dams, causeways, and piers
vallum, -ī [2/n]: wall; rampart; entrenchment
(4) cervus, -ī [2/m]: [i] deer; stag [ii] (from resemblance to the horns of a stag) cervī: forked stakes
(5), (7) fossa, -ae [1/f]: ditch; trench; moat
(6) turris, -is [3/f]: tower
(8) cippus, -ī [2/m]: sharpened stake
(9) līlium, -ī [2/n]: a form of defence, consisting of several rows of pits, in which stakes were planted, rising only four inches above the surface of the ground
(10) stimulus, -ī [2/m]: a sharp, barbed hook concealed beneath the surface of the ground, to repel hostile troops
