The word "naff" is a slang term that is commonly used to describe something that is uncool or unfashionable. Its antonyms, on the other hand, are the complete opposite of this meaning. A few antonyms for "naff" would include words such as stylish, sophisticated, trendy, fashionable, trendy or modern. These words are often associated with something that is in vogue, hip or chic. Using one of these antonyms in a sentence can convey a completely different meaning and impression than if you were to use the word "naff". Overall, the antonyms for "naff" are positive, upbeat and modern.