We have mentioned several times in class the idea of "Buffy speak," or, as this website dubs it, "Slanguage." So here it is: a complete dictionary of the sensationally quirky language of Buffy the Vampire Slayer.
This language is important in highlighting the extreme divide between youth and maturity that is prevalent throughout the series. Especially during the high school years, adults and teenagers seem to live in completely different worlds, with lines between them that are almost never crossed. Because of the extreme use of slang, adults barely even understand what the teens are saying to each other (as Giles makes note of on more than one occasion). In fact, it has been known to happen that viewers don't even understand everything they say with some of the more obscure pop culture references they constantly use (see "Keyser Sozed," for example).
Although this theme of the divide between teenager-hood and adulthood is more emphasized in the first few seasons of Buffy, it is actually present throughout the series. Even as the line begins to blur as the Scoobies grow into adults themselves, there is still a clear line between them and, for example, Giles. A third generation also comes into play as Dawn and the new Sunnydale High School students arrive, especially in Season 7.
All throughout, the language of the Buffy 'verse brings out the separation between generations. Some of the vocabulary begins to drop out after high school, but some of the words and phrases we know and love, like the verb "to dust," "the wiggins," and of course the phrase "The Scooby Gang" remain for all the years of Buffy. This unique language is one of the brilliant aspects of Buffy that serves to both make a point and give the fans some great new phrases to say.
Check out the link for the full dictionary, it's fun to see, especially if you know the whole series.