What Does Mecca Mean?

The word Mecca is of Arabic origin and probably it conveys the idea of being most important. As we all know that Mecca is the most important place for a Muslim and it is considered that every Muslim who is able bodied should visit the place at least once in his life time.
      
But the word is so popular that these days it has been taken into the English dictionary as a word that conveys the idea of something that is most important. You can use it for any thing that is of utmost importance in a particular area. The following sentence can make the meaning of the word quite clear as it is used in the context: London School of Economics is considered as the Mecca it its specific subject. The sentence says that the abovementioned institute is the best and considered as of prime importance if you want to study economics.

I am muslim, and today i saw a t-shirt that said mecca invasion...... Do that mean what i think that means?
Because up till this point i didnt know "mecca" in the english dictonary ment important......im asuming that it Dosent mean "important  invasion".