Quick, look it up as fast as you can! Precipitevolissimevolmente is the longest word in the Italian language. Derived from the adjective precipitevole, precipitevolissimevolmente is an adverb meaning 'as fast as you can'.
Other Italian word oddities include the word sovramagnificentissimamente. Used by Dante in "De vulgari eloquentia" in the 14th century, it means very, very, magnificent.