The dictionary frowns on words it snootily labels "informal." Teachers and newspaper copy editors carry a grudge against slang. Nearly everyone recoils from jargon. But according to a new book irresistibly titled "Slam Dunks and No-Brainers: Language in Your Life, the Media, Business, Politics, and, Like, Whatever," language purists now have another whole class of words to fret about: "pop words."

According to the author, former Village Voice columnist Leslie Savan, pop words are slang or edgily informal expressions that have gone mainstream, thanks to their adoption by the powerful. When politicians, pundits, columnists, corporate advertisers and television scriptwriters talk breezily about "crunching the numbers" or "getting a life," being "on the cutting edge" or "thinking outside the box," they are not -- in Ms. Savan's view -- really using slang, since everyone understands what they are saying.

Slang is niche speech, whether of the street or of the boardroom. Jargon is the slang of specialists. A snappy pop vocabulary, in contrast to both, is simply the lingua franca of much of America. (Other English-speaking countries have their own versions, but Hollywood-driven expressions have popped up all over the planet. People from Tokyo to Tehran know what a "bad hair day" is, or the importance of "doing the math.")