The Vietnamese word "nhơn" is a colloquial term often used in informal contexts. It can mean to act nonchalantly or brazenly, especially when someone is in a situation where they should feel guilty or ashamed but instead appear indifferent or unbothered.
Đang bị phạt mà vẫn cứ nhơn nhơn.
(Even while being punished, he still acts carefree.)
Cô ấy bị bạn bè chê cười mà vẫn nhơn nhơn như không có gì.
(She was mocked by her friends but acted as if nothing happened.)