Chalant

[Justin Bieber]

Extreme concern about an object.
Concerned

[Luis Fok]

not nonchalant.
Person- A calmed up person who is ready to raise the roof and will call you out for being lame because theyre 10 steps ahead of you in the game. Probably hollers and yaks a lot.

[Couch Potatoe]

The opposite of [nonchalant]. Getting straight to a topic or not beating around the bush.

[Sonia]

Opposite of nonchalant. Worried, hurried, not cool.