Ideas can't be protected by copyright, only the expressions of them; the novel will automatically be protected once it's written down, but not until then.
You could apply for a patent. Contact the US Patent Ofiice for information on how.
The cast of A Novel Idea - 2013 includes: Nate Ocansey as Dead Darrin
Now there's a novel idea!
protect his/her head
This is usually called the expression of the idea. I can't protect my idea for a movie, but I can protect my script.
the idea of a novel, poem , or story
There aren't many -- read through these links to get an idea of how to write a novel!
Submit novel
The author wrote a very descriptive and interesting novel. Or: It was so innovative and unique, it was truly a novel idea.
Vince Flynn
Nice idea for a novel!
novel