We can divide obsolete Japanese vocabulary into two categories: kogo 古語, “old words,” and shigo 死語, “dead words.” Kogo held respectable careers in pre-modern Japan but retired quietly at some point before the Meiji restoration. Shigo are more recent and violent casualties — many began as conscious neologisms in response to the same accelerating social change that would later render them irrelevant. All shigo once rubbed shoulders with the surviving portion of modern Japanese. Kogo haunt the language with dignity, like ghosts in an ancestral mansion; shigo lie unquiet in shallow graves out back. There is a reason that shigo are also known as haigo 廃語: “abandoned words.”
Naui 「ナウい」was a mayfly of a word, declared dead almost as soon as it was born, reviled as a desperate attempt to squeeze a few more youth dollars out of an already-uncool borrowed English lexeme (“now”). As a word in its own right, nau had already demonstrated a tenacity rivaling Madeline Usher’s, but naui was fated to surpass its progenitor in every respect. It became a lexicographic Cartaphilus ― cursed to wander the sentences of Japanese forever, scorned and reviled but never granted the peace of oblivion. Its unforgivable sin? To once have both been and meant “fashionable.”
According to Takahashi Nobuo’s dictionary of Showa buzzwords (「昭和世相流行語辞典―ことば昭和史 WORD&WORDS」), naui’s story begins in 1972 — the year that nau entered the language as a bona-fide loan word, written in kana and used as a na adjective. This was a logical development, Takahashi notes, from the popularity of English NOW (in Roman characters) used in similar contexts the previous year.
Nau collocates closely with yangu (“young”), as in nau na yangu (“the groovy youth of today”). Nau and nau na yangu even share an entry in the first volume of Kobayashi Nobuhiko’s Contemporary Shigo Notebook (『現代「死語」ノート』). Kobayashi deems nau “a shigo among shigo,” one that is “just plain embarrassing.” He also claims that even back then, it was used “less by actual young people than by adults pandering to them,” and that it died almost immediately.
Naui itself, then, is an -i adjective derived from the same English root. It seems to have turned up at the end of the seventies in what Kobayashi, in the second volume of his Notebook (『現代“死語”ノート〈2〉1977‐1999』), calls a “shigo counteroffensive.” The online Dictionary of Japanese Slang also places the birth of naui in 1979.
Back then, naui wasn’t without competition. For example, imai 「今い」, was a roughly contemporaneous and structurally identical synonym based on the Japanese word for “now” instead of the English one. But naui bested all contenders on sheer charisma. The precise image it invokes of an awkward middle-aged man finger-quote “rapping” with the finger-quote “kids” kept it in the vocabulary of both middle-aged men oblivious to their own awkwardness and all those embarrassed by and for same. (This blog entry traces the survival of naui in literature and the media through the Famicom age and beyond, even expressing doubts as to whether naui deserves its shigo status at all.)
One interesting recent appearance of naui was in the straight-to-convenience-store Cyclopedia of Messed-Up Heisei Words (『図解 平成ぶっこわれコトバ事典』) of 2005. This grave and scholarly work records naui yatsu as an ironic term applied to people who are insufficiently fashionable. In some cases, then, naui has come to mean its own opposite: to be called naui is to be mocked for insufficient, well, now-ness.
If indeed naui is to be deprived even of the right to mean what it means, perhaps the correct metaphor is not Wandering ‘Djective but Struldbrug: “looked on as dead in law” but nightmarishly alive, imprisoned in an increasingly ridiculous and pitiful form and reduced to begging for whatever scraps of favor it can get.