debouch
A narrow outlet from which a body of water pours.
In level portions of the country vertical shafts are preferred, but where the mine is situated upon a hill a debouch may often be found below the sulphur seam, ...
A fortress at the end of a defile.
To prevent another demonstration of this character, and to insure a debouch on the south bank of the James, it became necessary to occupy Coggin's Point, which was done on the 3d, and the enemy driven back towards Petersburg.
Where it comes from
From French déboucher (de + bouche (“mouth”)), modelled on Italian sboccare.
Adapted from the Wiktionary entry debouch (CC BY-SA 4.0).