"Voila" for idiots.

"Voila" is French for "Look Here" but people who are clueless sometimes say or spell it "Wa-lah" because the French do not pronounce the "V" as clearly as English speakers would.

Mercury retrograde is the act of taking a shit whilst mooning one or more human beings. Your day can typically being going well, according to your horoscope, until you are forced into witnessing Mercury retrograde. Performing Mercury retrograde will often speed the astrological cycle forward for the individual performing the Mercury retrograde, bringing about happy and fruitful times to come.

To define a moment of excitement or extreme happiness. Also can be said after any sentence in the phrase "say walah".

I swear, it's really sacred and you shouldn't use it unless you statement is real, honest and truthful.