nonchalance
n. 冷淡；漠不关心；冷静
例句
Affecting nonchalance, I handed her two hundred dollar bills.
我假装若无其事地递给她两张百元钞票。
《柯林斯英汉双解大词典》
She was very tense, but she preserved an appearance of nonchalance.
她内心很紧张，可外表却装着满不在乎的样子。
《新英汉大辞典》
The Discovery Center is the opposite: all transparency and nonchalance.
这个探索中心是相反的：所有的都是通透的也是冷淡的。
