Translation

落ち着きすぎた / 堅実な / 面白みに欠ける

Meaning

Staid describes someone or something serious, respectable, and calm, but often rather dull or old-fashioned. It is a judgment about style or personality. Do not confuse it with stayed, the past form of stay.

Examples

• そのホテルは堅実だが、少し古くさい雰囲気だった。
  The hotel had a staid but slightly old-fashioned atmosphere.
• 彼は若いチームにしては驚くほど落ち着いた服装をしていた。
  He dressed in a surprisingly staid way for such a young team.