How to say "strait" in Japanese

• 海峡かいきょうJLPT N1approx.Common
  nounA strait in the basic geographic sense: a narrow passage of sea between two land masses. Use it when describing coasts, shipping routes, or a crossing between islands and the mainland.
  アメリカンインディアンの祖先そせんは、ベーリング海峡かいきょうを経由けいゆしてアジアから米べい大陸たいりくへ渡わたった。↗

  The ancestors of Native Americans went to the continent from Asia by way of the Bering Strait.
• 瀬戸せとCommon
  nounA native word for a strait or channel, especially the narrow waters between islands; it is best known from place names, where learners most often encounter it.
  名古屋なごやと言いえば、あなたは瀬戸せとへ行いったことはありますか。↗

  Speaking of Nagoya, have you ever been to Seto?
• 水道すいどうJLPT N4approx.Common
  nounIn everyday language this word means the water supply or a tap; its sea-passage sense is chiefly nautical, appearing in the names of channels, so it is seldom the word you want for 'strait'.

Use 海峡 for a strait as a geographic feature; 瀬戸 is the native word for a channel between islands, familiar chiefly from place names; 水道 ordinarily means the water supply, its 'channel' sense being mainly nautical.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 海峡かいきょうchannel (e.g. between two land masses)
• 瀬戸せとstrait
• 海門かいもんstrait
• 水道すいどうchannel