KIDS SAY their parents don't understand them, or their teachers either, and they may never have had better documentary evidence than the newly released dictionary of "Slang: Words and Terms" compiled by an official of the New York City public school system. Dictionaries of slang aren't new, but this one's stated purpose is genuinely novel: to translate enough of students' language so that their teachers can figure out what they are hearing. The reason teachers want to be able to do this -- or, to put it another way, the reason the book is by an official of the Division of School Safety -- is that most of what students are talking about in an ever-more-intricate slang is drugs, fights and crime. This seems to hold true not just for conversations among kids themselves but even for the attempts they make to talk about drugs, fights and crime to sympathetic adults. That at least was the experience of Peter Commanday, the compiler and a former discipline dean in a South Bronx junior high school. "I had all these degrees," he told the Associated Press, "and these kids were speaking to me, and I did not understand what they were saying."

Slang being slang, what they were saying then is probably outmoded by now. But here, at least, is the sort of thing Mr. Commanday and his field informants were able to get down on paper: you "beam up" on crack, but get "shermed" on PCP; to "base" means to argue, and a "joint" is a fight, and the concept that a prehistoric teenager might have expressed as "high" now translates as "zootie." Some of the 221 terms suggest that this language forms with the same grace and unexpected connections as any language (to "audi" is to run), and some is downright impenetrable, as was probably its intention.

But if, as linguists aver, slang is essentially a code to mark off insiders from outsiders -- or, more benignly, a sort of specialized jargon to show off expertise -- the width of this particular chasm in the schools suggests other possibilities. Linguists have also come across societies where separate and mutually incomprehensible languages developed for different social classes or, in extreme cases, for men and women.

Distinct languages for younger folk and older folk may not be all that much more farfetched. (Nor, for that matter, is the idea of the New York City public schools giving rise to linguistic phenomena never seen elsewhere.) As for the dictionary, though, it seems unfortunate for adults to do all the work on bridging this quickly widening gap. Maybe the rule should be this: any teacher who wants a copy of "Slang: Words and Terms" must first locate a student who has agreed to have a look at Webster's.