城郭・城廓|じょうかくjoukaku[0]heiban (flat)

1. nouncastle; citadel; fortress
2. nouncastle walls; enclosure

• Synonym城しろNeutralThe everyday, most common word for a castle, as in 「大阪城」; compared with it, 「城郭」 stresses the castle's overall structure.
• Related砦とりでNeutralA defensive stronghold stressing its role as a military facility; usually smaller in scale than a castle.
• RelatedシャトーNeutralLoanword for a French-style castle or wine estate; quite different from a Japanese castle.
• Related要塞ようさいNeutralA military fortress, often built at national borders or on coasts; purely military in emphasis.
• Related城塞じょうさいWrittenA written-style word covering both castle and fortress, with emphasis on the defensive function.
• RelatedキャッスルNeutralLoanword for a Western-style castle, often seen in shop names or theme parks.
• Related館やかたNeutralA noble's mansion or residence; the emphasis is on the dwelling, which need not be castle-sized.
• Related要害ようがいNeutralA naturally strong position or stronghold, stressing the terrain, as in 「天然の要害」.

In daily speech, use 「城」. 「城郭」 suits castle walls, a castle's overall structure, or academic contexts. For military fortresses, 「要塞」 or 「砦」; 「城塞」 is a written word. 「シャトー」/「キャッスル」 cover Western castles, 「館」 a noble's residence, 「要害」 strategic terrain.

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

1. 城しろと郭かく。城しろの郭かく。
2. 城塞じょうさい。