The word naff, as we use it to day, can mean "of low quality" or "of poor standards" it can also be used to replace the F word as in "naff off". However if you go back to the 1840's it was being used in a different contex. Spelt with only one F, "naf" derives itself from back slang and comes from the word used, in the UK, to descibe the female sexual organ.
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