n. a ditch dug as a fortification having a parapet of the excavated earth
n. a long steep-sided depression in the ocean floor
n. any long ditch cut in the ground
v. fortify by surrounding with trenches
n. 渠, 沟渠, 战壕
vt. 在...开沟, 挖战壕于, 用战壕围住
vi. 挖战壕, 开沟