Much of the modern slang commonly used today in both British and American English has its origins in colloquial African-American language from the first half of this century. This type of speech became 'hip' or 'cool' in the 50s and 60s through the lifestyle and writings of America' s Beat Generation, the growth of rock ' n roll (itself an African-American term originally referring to sex) and the hippie movement. Nowadays many of these words are so widely used that they can hardly be still considered slang - many are even listed in dictionaries.