President Trump with his daughter and adviser Ivanka. (AP Photo/Pablo Martinez Monsivais)

Today was a productive vocabulary day in the United States of America.

The learning began in the morning, when former CIA director John O. Brennan tweeted at President Trump: “Your kakistocracy is collapsing after its lamentable journey.”

The insult was part of a raging feud between Trump and various members of the intelligence community, some of whom suspect the president’s inner circle of committing federal crimes, and many of whom Trump says are out to destroy him.

Brennan’s tweet proved quite popular with Trump’s critics, even if not everyone totally understood it.

What, wondered the actor/director Zach Braff and the fake congressman Steven Smith, and many others, was a “kakistocracy”?

Kleptocracy means a government by thieves, and autocracy means government by one person. Both of those terms have been used liberally by Trump’s critics in the last year or so, but kakistocracy … was that like a government of cack, as in dung?

Actually, yeah, kind of.

Searches for the kakistocracy surged to the top of Merriam-Webster, arguably the hippest of the major dictionaries, which recently made “dumpster fire” an official English word.

So Merriam-Webster wrote a short explainer. Kakistos is Greek for “worst,” so kakistocracy means government by the worst people.

The plural is kakistocracies, the dictionary added, in case the world one day ends up with two of them.

Merriam-Webster traced the word’s first known use to a 159-word sentence in a sermon by a supporter of King Charles I during the English Civil War in 1644.

It’s too amazing to excerpt, so buckle in:

“We need not make any scruple of praying against such,” the speaker Paul Gosnold said of the king’s enemies, “against those Sanctimonious Incendiaries, who have fetched fire from heaven to set their Country in combustion, have pretended Religion to raise and maintain a most wicked rebellion, against those Neros, who have ripped up the womb of the mother that bare them, and wounded the breasts that gave them suck, against those cannibals who feed upon the flesh and are drunk with the blood of their own brethren, against those Catilines who seek their private ends in the public disturbance, and have set the kingdom on fire to roast their own eggs, against those tempests of the State, those restless spirits who can no longer live, then be stickling and meddling, who are stung with a perpetual itch of changing and innovating, transforming our old hierarchy into a new Presbytery, and this again into a newer Independency; and our well-tempered Monarchy into a mad kind of Kakistocracy.

“Good Lord!” he continued (sorry, we don’t want to break up his rhythm). “What wild irregular courses have these men run, since the reins have lain loose upon them? I am afraid, they will never leave chopping and changing, plotting and practicing, till in conclusion they bring all to confusion, all to an Anarchy or savage Ataxie, Prayer, Peace, Jerusalem, and all.”

Gosnold’s side eventually lost the war. Anyway, Brennan wasn’t the first person to use the word after him. It appeared in the epigraph of a 1992 book about Dan Quayle, and then the name of a Tennessee punk band.

Paul Krugman rolled the word out in the New York Times near the beginning of Trump’s presidency: “An American kakistocracy — rule by the worst.”

This isn’t even the first time it’s surged on Merriam-Webster. The dictionary had to explain the word last summer, too, after MSNBC host Joy Reid used it, once again, to drag Trump.

This time, however, kakistocracy blew up the charts, with dictionary searches spiking nearly 14,000 percent after Brennan’s tweet.

The second most popular word of the day was “slimeball,” which had been Trump’s verbiage in the tweet to which Brennan was replying.

This article originally stated incorrectly that Gosnold was addressing British Parliament. His sermon is labeled as such, but he was actually addressing the king’s loyalists in Oxford, who called themselves Parliament even though they were at war with the actual Parliamentarians who went on to win the English Civil War.

More reading:

‘Feminism’ is Merriam-Webster’s word of the year, thanks in part to Kellyanne Conway

Congratulations, everybody: ‘Dumpster fire’ is now a dictionary entry, and here’s why