Sirius. I mean, who names their kid after an expression? especially since sirius was anything BUT serious. Thats like me naming my kid "austere" or "deliberative". Yuk. He probably got beat up too. AND "serious" is even spelled wrong!!

O.O You have GOT to be kidding me. No, just no. Sirius is named after DOG STAR not the adjective. Plus is really creative given how his animagus is a dog. Trust me, it's spelled right.
Props for using words like "austere" and "deliberative" though