1966, in the meaning defined above
perhaps borrowed from Polari (English argot used by theatrical and circus performers and in certain gay subcultures, derived in part from Italian); ulterior origin uncertain
Note: A summary of hypotheses on the origin of naff can be found in the Oxford English Dictionary, on-line third edition (this entry updated June, 2003). The putative Polari phrase naff omi “a dreary man,” unattributed in the Oxford etymology, is apparently from a communication by the comic actor Kenneth Williams, in 1980, to Paul Beale, the editor of Eric Partridge’s A Dictionary of Slang and Unconventional English, 8th edition, 1984 (see p. 775).