The Collaborative International Dictionary of English v.0.48:

Tete-de-pont \T[^e]te`-de-pont"\ (t[=a]t`de*p[^o]N"), n.; pl.
   T[^e]tes-de-pont. [F., head of a bridge.] (Mil.)
   A work thrown up at the end of a bridge nearest the enemy,
   for covering the communications across a river; a bridgehead.
   [1913 Webster]