nonchalance
🇺🇸
/ˌnɑːnʃəˈlɑːns/
🇬🇧
/ˈnɒnʃələns/
When someone is calm and does not seem worried or eager.
She answered the questions with nonchalance, looking completely relaxed.
彼女は質問に対して無関心を装い、完全にリラックスした様子で答えた。