From charasso (to sharpen to a point; akin to grapho through the idea of scratching); a stake, i.e. (by implication) a palisade or rampart (military mound for circumvallation in a siege) -- trench.
see GREEK grapho
1. a pale or stake, a palisade ((Aristophanes, Demosthenes, others)).
2. a palisade or rampart (i. e. pales between which earth, stones, trees and timbers are heaped and packed together): Luke 19:43 (Isaiah 37:33; Ezekiel 4:2; Ezekiel 26:8; Polybius; Josephus, Vita43; Arrian exp. Alex. 2, 19, 9; Plutarch, others).