In young people's slang (especially in the US): def, 'hip', 'cool', new and exciting. Etymology: A sense shift which is perhaps influenced by the pun with cool; as a word of approbation in young people's slang it has its roots in rap talk and ultimately in the street language of hip hop. History and Usage: This is a usage which only began to appear in print in the second half of the eighties, as part of the crop of new slang expressions popularized by the spread of hip-hop culture. A number of rappers used the word in their pseudonyms, and a US sitcom which was centred on hip hop and shown on UK television as well had as its title The Fresh Prince of Bel Air. Run DMC, the rap group, told it to the audience straighter than most. The other groups at the Fresh Festival, a compendium of rappers and break dancers, had visited Hollywood. Chicago Tribune 7 July 1985 (Final edition), section 3, p. 5 According to Freddy, street talkers and rappers long ago abandoned bad for such alternatives as fresh, def and chillin'. Los Angeles Times 29 Aug. 1988, section 6, p. 2

English colloquial dictionary, new words.      Английский разговорный словарь - новые слова.