Mil. [ad. F. avant-fossé, after vanguard, etc., and FOSSE.] (See quots.)
1728. Chambers, Cycl., Van-Fosse,… a Ditch dug without the Counterscarp, and running all along the Glacis; usually full of Water.
1852. Burn, Naval & Milit. Dict., II. 304/1. Van-foss, avant-fossé.
1867. Smyth, Sailor’s Word-bk., Van-fosse, a wet ditch at the outer foot of the glacis.
