To throw a person or thing out of a window. Literally. There is a window. You know what to do.
We are outside, looking in. Through the tall front window stands the giant, a queue of difficulties waiting beside him — a councillor, a bug, a crashing window, an unwanted memo. He takes the one at the front, winds up, and hurls it sideways; it bursts out the broken pane of the side window and tumbles down onto the ground, where the heavy councillor thuds short and the weightless memo flutters far. The problem is not solved. The problem is outside, which — to the giant, dusting off his hands — is very nearly the same thing and a great deal faster.
From Latin de-, “down or out of,” and fenestra, “window.” Defenestrate means to throw out of a window, and means nothing else. Few words in English wear their definition this plainly. It was built for one purpose and has never needed a second.
Hussite reformers storm the New Town Hall and hurl the judge, the burgomaster, and several councillors from the windows onto the pikes of the crowd below. The First Defenestration of Prague ignites the Hussite Wars. The act is so specific it will, eventually, demand its own verb.
Protestant nobles throw two Catholic regents and their secretary from a high window of Prague Castle. All three survive — landing, by most accounts, in a heap of manure. The Second Defenestration of Prague touches off the Thirty Years' War, one of the deadliest conflicts Europe would ever see.
Defenestration enters English in the wake of these events, minted specifically to name the Prague incidents. The language looked at what the Bohemians kept doing to people through windows and decided it warranted a dedicated, dignified, Latinate word. It was right.
By the modern era the verb sheds its glass. To be defenestrated is to be ousted — from a board, an office, a cabinet — suddenly and without ceremony. The image survives intact: one moment you are inside, the next you are very much outside, and the transition was not gradual.
Programmers, handed a word that literally means throwing Windows out, did the only thing programmers do. The pun is irresistible and ancient by internet standards, deployed every time someone migrates off an operating system with more feeling than strictly necessary.
The word endures because no synonym does the job. Eject is clinical, discard is gentle, throw away lacks the window. Defenestrate keeps a six-hundred-year-old precision: the arc, the glass, the ground below. Some words resist resurrection. This one only ever needed a window, and there is always a window.