fosse (n.)

• aqueduct
• bunker
• canal
• canalization
• channel
• countermine
• crimp
• cut
• dike
• ditch
• dugout
• entrenchment
• foxhole
• gallery
• goffer
• gutter
• ha-ha
• kennel
• mine
• moat
• parallel
• pleat
• sap
• trench
• trough
• tunnel