Translation

自己満足 / 慢心 / 油断

Meaning

Complacency is a self-satisfied lack of worry, effort, or caution, especially when there is still risk or work to do. It is usually negative because it makes people stop improving or preparing.

Examples

• その勝利の後、チームには慢心が見られました。
  After the victory, the team showed signs of complacency.
• 安全管理での油断は重大な事故につながります。
  Complacency about safety can lead to serious accidents.