This isn't very heavy duty, in the scheme of things.

But, here's a blue clicky for the word gravitus:

http://www.websters-online-dictionary.org/translation/Latin/gravitus

So could Websters' online dictionary be wrong?

I'm shocked!! Simply shocked!

Maybe they made up that word. Why not? Other people make up words all the time. Folks in the Hip-Hop community are rather good at making up words 24/7 every hour of the day, seven days a week.

[You say that's what 24/7 means?]

Oh. Yeah. That's right.