GIRL POWER, dweebs, babes and even dangly bits may soon creep into pupils' essays after making it into Roget's Thesaurus.
Students will also learn that bad can mean good and sad pathetic from the new Collins English Dictionary due out next month.
Chambers' new edition, also to be published in September, introduces new words: phat meaning excellent, wonk meaning a serious or studious person and doofer, which replaces the humble thingummy as the thing you have forgotten the name of.
The new reference books aim to reflect the changes in education, technology and everyday speech.
But teachers' hearts may sink at the trends lexicographers have ruled are here to stay. Cyberpets receive official recognition in Roget's new edition - the first for 11 years.
OFSTED, SATs and dumbing down also make their first appearance in the Collins dictionary, last published in 1994.
When Peter Mark Roget compiled his first book of words and phrases in 1852, education league tables were not even a twinkle in education ministers' eyes.
Yet they make their Roget's debut this year along with learning curve, level playing field, adhocracy and Back to Basics.
It took Roget more than three years of "incessant occupation" to classify 15,000 words into 990 categories. That unique classification has stood the test of time, according to editor Betty Kirkpatrick who selected this year's 250,000 entries.
Mrs Kirkpatrick said: "There are probably some things included this time that people wish weren't. We mention illegal substances, recreational drugs and Ecstasy but this seems to be a major part of youth culture so it was right that they be included."
Ruth Killick of publishers Penguin said the new additions probably echoed what teachers already heard in the classroom.
She said: "A lot of the expressions are the ones coined by kids. The new words are often taken from youth culture so they were probably bandied around the classroom long before they were included in the thesaurus."
Conditions which cause pupils learning difficulties are also included for the first time. Dyscalculia and dysgraphia are introduced to describe difficulties in adding up and writing, while dyspraxia, the impaired ability to perform deliberate actions, is included in Roget's for the first time. Attention deficit disorder is also included by Collins.
Collins lexicographer Ian Brookes said: "There have been a number of innovations in education since our last edition. Education was one of our key subjects which we completely revised to reflect the changes.
"It was striking how many computer terms were added. It is an area of language that is constantly changing and that many young people probably know more about than their parents or teachers."
Collins also included Britpop, gangsta, jungle and garage music.
Mr Brookes added: "To some extent a dictionary always has to lag a little behind the times because we have to see whether the words will survive. We can't always be as trendy as we might like."
Opinion, page 10