nonchalance rhymes like No + Challenge , When there is no challenge, people tend not to care and there will be a casual lack of concern.
Chalan(Govt)...Fine...so unchalance..not concerned
anuj : abbey helmet to pehen le <br> me : no worries, dad is in govt. NO CHALAAN for me, <br> anuj: man don't be so nonchalance
nonchalance -> non to chalenge with me, unconcern, lack of concern, indifferent