Today’s word is idle, something I never am.
Did you believe that? Because I didn’t.

Idle comes from the Old English idel, empty, vain, or worthless. It’s West Germanic in origin, although there’s not much info on it, certainly not where it came from before that. I guess the word should have gotten out and made a name for itself.
Is that it? Huh, that’s it. Later, everybody!
Sources
Tony Jebson’s page on the Origins of Old English