巣窟

1. Origins, structure, and basic meaning

• Structure: Spelling: 巣窟. Reading: そうくつ. Core meaning: den; stronghold.
• Basic usage: Representative examples: 探偵小説の廃屋は盗賊の巣窟になっていた / 古い塔を悪者たちの巣窟として舞台に再現した.

2. Common pitfalls and similar expressions

• A den for a disreputable group
  • 巣窟 is a den or stronghold where thieves or villains gather and usually carries a negative judgment. Its tone differs from neutral 巣, an animal's nest.