Defining a Word

Words have the ability to conjure up images in our minds. Some, such as the word no, can be used to convey all sorts of meanings when certain tones and facial expressions are given. Other words defy description. One such word is hooah. What exactly does it mean? It's used extensively in the US Army and I've seen it at numerous milbloggers. The Urban Dictionary gives several definitions. The following are two that seemed most reasonable.

Phonetic spelling of the military acronym HUA, which stands for "Heard Understood Acknowledged." Originally used by the British in the late 1800's in Afghanistan. More reciently(sic) adopted by the United States Army to indicate an affirmative or a pleased response.1: Sgt: "Y'all got the game plan?"
PFC(s): "Hooah sargeant(sic)!"

U.S. Military Slang.

Referring to, or meaning anything and everything except "no." Generally used when at a loss for words. Also:

Good copy, solid copy, roger, good or great; message received, understood.
Glad to meet you, welcome.
I do not know, but will check on it, I haven't the vaguest idea.
I am not listening.
That is enough of your drivel--sit down.
Stop sniveling.
You've got to be kidding.
Yes.
Thank you.
Go to the next slide.
You have taken the correct action.
I don't know what that means, but am too embarrassed to ask for clarification.
That is really neat, I want one too.
Amen.

From the second definition, hooah is a very diverse word. I like 'stop sniveling' and 'that's really neat, I want one too'. What's your favorite use?