noun
moat
MOHT/məʊt/
A deep protective ditch enclosing a defended place.
A deep moat surrounds the castle and helps protect it.

Etymology
Old French mote named the castle mound, but the meaning shifted to the defensive ditch surrounding it. The word’s deeper origin is unknown.
In context
the castle was situated in the midst of a small island surrounded by a moat 30 ft deep and 20 ft wide over which lay a drawbridge
More examples
- Visitors cross the moat on a narrow bridge.
- The fort's dry moat makes its walls harder to reach.
- Some castles have moats filled with water.
Forms
moat · moats