to act as though unbothered, or in a fashion that would show as though nothing happened
The man was nonchalant
Nonchalant was born on 1970-10-18.
Nonchalant, he lifted her skirt, (which was hanging on the clothesline).
Example sentence - He acted quite nonchalant about the evening with her.
You could say: Nathan's heart was beating loudly and feared his girlfriend would hear it, however he continued to act nonchalant.
Not necessarily but a nonchalant attitude can be viewed as noncaring or detached.
Nonchalant.
I couldn't understand how she could be so nonchalant about a job interview with such a prestigious law firm.
If you are nonchalant instead of remorseful, the judge will give you a very strict prison sentence.
Nonchalant.
The noun is nonchalance.
"The young composer was very nonchalant about winning the Pulitzer Prize for music, as if it were something every young composer did."