Without a doubt.
*Also can be used to confuse the shit out of idiots.
Person that reads: I concur.
Black kid: (Confused look) Does that mean you agree?
Person that reads: Indubitably.
Black kid: (Head EXPLODES!)
Ok, this is the best word in the english language. Just say it and it gets plastered into the back of your brain and you're hooked on this one word. Saying it over, and over, and over, and over. I love it.