Translation guide
A moat is a deep, wide ditch surrounding a castle, typically filled with water. In Japanese, the word 堀 (ほり) covers moats, canals, and ditches. This guide focuses on castle moats and related expressions.
Referring to the defensive water-filled ditch around a Japanese castle
The standard word for a moat, canal, or ditch. In a castle context, it means moat. Often combined with other words like お堀 (おほり) for politeness or 外堀 (そとぼり) for outer moat.
この城の周りには広い堀があります。
There is a wide moat around this castle.
お堀には鯉が泳いでいます。
Carp are swimming in the moat.
Polite prefix お + 堀. Commonly used when referring to castle moats in a respectful or tourist context.
皇居のお堀はとても美しいです。
The Imperial Palace moat is very beautiful.
Distinguishing between outer and inner defensive moats
Outer moat. Often used metaphorically in business or strategy (外堀を埋める = to surround/isolate an opponent).
外堀は内堀より広いです。
The outer moat is wider than the inner moat.
Inner moat, closer to the castle keep.
A moat without water, often with steep walls
Literally 'empty moat', a dry moat. Common in Japanese castle design.
この城には空堀が残っています。
This castle still has a dry moat.
Using 'moat' in a figurative sense, like a competitive advantage
Economic term for 'barriers to entry', often translated as 'moat' in business contexts (e.g., 'economic moat').
この会社の参入障壁は高いです。
This company has a strong moat.
Literally 'build a moat', used metaphorically to mean creating a defensive barrier or advantage.
競合他社に対して堀を築く必要があります。
We need to build a moat against competitors.
When talking about famous castle moats (e.g., Imperial Palace, tourist sites), using お堀 (おほり) sounds more natural and respectful. In historical or technical descriptions, plain 堀 is fine.
堀 is a large moat or canal, while 溝 is a small ditch or groove. Don't use 溝 for a castle moat.
内堀は今は埋め立てられています。
The inner moat has been filled in now.