Learner's definition of NONCHALANT
[more nonchalant; most nonchalant]
relaxed and calm in a way that shows that you do not care or are not worried about anything
He was surprisingly nonchalant about winning the award.
She faced the crowd with the nonchalant ease of an experienced speaker.
The team may have been somewhat nonchalant at the beginning of the season, but they now know that they need to work hard.