The word extravaganza was imported from the Italian to describe an extravagant type of writing that was terribly popular in the nineteenth century. The Victorian stage was filled with extravaganzas, which were defined, by one of their chief exponents, as the whimsical treatment of a poetic subject.
Extravaganza was merely the Italian term for an extravagance, and nowadays, of course, you can have an extravaganza of Christmas trees or shopping or whatnot. Anything faintly over the top can be an extravaganza.
So far, so fun. But regular readers of this blog will know that I have a penchant and peccadillo for vagant words. You see, the vagant in extravagant just means wandering, and an extravagance was merely a wandering beyond the limits. That means that I've also been able to post on the English words noctivagant (wandering around at night), montivagant (wandering over mountains) and omnivagant (wandering absolutely everywhere).
This opens the delightful possibility that if you spent the whole night wandering around it would be a noctivaganza, and that a week's walking holiday in the Alps might count as a montivaganza and so on and so forth.
All of this was suggested to me by Paul Norman of Books Monthly who has just written a very complimentary review of my book The Etymologicon, which you can read here (it's on the left of the page).
I think the third from the left may be a crafty man.