Linguists have a good number of fancy words to describe language evolution. When a word’s meaning becomes more negative over time it is referred to as pejoration. When the meaning changes to be closer to a more approved meaning, it is called melioration. It is quite common to see a word change in one direction; some words even manage to change in both directions. Two such words that have managed to see-saw like this are Nazi and fascist.
Both of these words began as descriptors, rather than epithets. Each one referred to a political party; Nazi is a shortened form of Nationalsozialist (the National Socialist German Workers’ Party), and fascist came from the Partito Nazionale Fascista (the National Fascist Party in Italy). The actions of each of these groups during the Second World War caused their names to become synonymous with ruthless authoritarianism and unparalleled brutality.
So there we have the initial movement, pejoration. Following the war we didn’t have nearly as many Nazis and fascists as we once did, and so the words then began going through the reverse movement, melioration.
Fascist began its melioration much sooner than Nazi did. The Oxford English Dictionary records metaphorical use of this word as early as 1945, to describe someone who is intolerant or unduly coercive. Nazis, perhaps due to the fact that the enormity of their crimes was so much greater, had to wait until the 1980s before people began to use their title as shorthand for “pushy person who is trying to get me to improve something that I’d rather not be bothered with.”
In the relatively recent past Nazi (often spelled with a lowercase n), has been working its way into general language. One can see examples of supposed nazis modified by fitness, food, fashion, and so on. Perhaps the most common one recently is the grammar Nazi. The term for this curious creature dates back to at least 1991, when a member of a Usenet group (for younger readers out there, this is essentially an early online forum) entered the message “I’m a card carrying member of the Spelling and Grammar Nazis of America.”
It must be said that many people find the modified use of these words (and especially that of Nazi) to be awkward at best, and extremely insensitive at worst. The destruction and cruelty associated with these words is so strong that in 2014, the New York Times reported that the Israeli parliament was working on a bill to make the act of calling someone a Nazi a crime; the offender could be jailed for up to six months, and fined as much as $29,000.
Grammar Nazis, however much they might annoy with their protestations of correctness, are not actual Nazis. At least not most of the time.
Last year much of the Internet exploded with a combination of delight and bemusement when the American Nazi Party tweeted “It really isn’t that difficult to use correct spelling and grammar. Be professional and disciplined in everything that you do for the cause.” Finally, here was a literal Nazi, angry about grammar; an honest-to-goodness grammar Nazi. The authors of this tweet are quite possibly the only ones who should self-identify with this term.