from
The Collaborative International Dictionary of English v.0.48
Debouch \De*bouch"\, v. i. [imp. & p. p. {Debouched}; p. pr. &
vb. n. {Debouching}.] [F. d['e]boucher; pref. d['e]- (L. dis-
or de) + boucher to stop up, fr. bouche mouth, fr. L. bucca
the cheek. Cf. {Disembogue}.]
To march out from a wood, defile, or other confined spot,
into open ground; to issue.
[1913 Webster]
Battalions debouching on the plain. --Prescott.
[1913 Webster]
2. (Geog.) To issue; -- said of a stream passing from a gorge
out into an open valley or a plain.
[Webster 1913 Suppl.]