9. The Army on the March
The latter defined as "places enclosed on every side by steep banks, with pools of water at the bottom.
Defined as "natural pens or prisons" or "places surrounded by precipices on three sides—easy to get into, but hard to get out of."
Defined as "places covered with such dense undergrowth that spears cannot be used."
Defined as "low-lying places, so heavy with mud as to be impassable for chariots and horsemen."
Defined by Mei Yao-ch`en as "a narrow difficult way between beetling cliffs." Tu Mu's note is "ground covered with trees and rocks, and intersected by numerous ravines and pitfalls." This is very vague, but Chia Lin explains it clearly enough as a defile or narrow pass, and Chang Yu takes much the same view. On the whole, the weight of the commentators certainly inclines to the rendering "defile." But the ordinary meaning of the Chinese in one place is "a crack or fissure" and the fact that the meaning of the Chinese elsewhere in the sentence indicates something in the nature of a defile, make me think that Sun Tzu is here speaking of crevasses.