http://dictionary.reference.com/search?q=debouch
And here is the obsolete bouch.de·bouch /dɪˈbuʃ, -ˈbaʊtʃ/ Pronunciation Key - Show Spelled Pronunciation[di-boosh, -bouch] Pronunciation Key - Show IPA Pronunciation
–verb (used without object)
1. to march out from a narrow or confined place into open country, as a body of troops: The platoon debouched from the defile into the plain.
2. Physical Geography.
a. to emerge from a relatively narrow valley upon an open plain: A river or glacier debouches on the plains.
b. to flow from a small valley into a larger one.
3. to come forth; emerge.
–noun
4. débouché.
[Origin: 1655–65; < F déboucher, equiv. to dé- dis-1 + -boucher, v. deriv. of bouche mouth < L bucca cheek, jaw]
http://dictionary.reference.com/browse/bouch
Bouch
e \Bouche\, Bouch \Bouch\, n. [F. bouche mouth, victuals.] 1. A mouth. [Obs.]
2. An allowance of meat and drink for the tables of inferior officers or servants in a nobleman's palace or at court. [Obs.]