Ackshually it’s from Neo-Latin ‘fenestra’ meaning ‘window’, specifically coined in 1620, presumably as ‘defenestratio’:
A word invented for one incident: the “Defenestration of Prague” (May 21, 1618), in which two Catholic deputies to the Bohemian national assembly and a secretary were tossed out the window of the castle of Hradschin by Protestant radicals. The trio landed in a trash heap and survived, but it marked the start of the Thirty Years’ War.
‘Fenster’ was borrowed from Latin as ‘*fenestr’ way back in the times of Proto-West Germanic. Which, to my understanding, is a somewhat unusual behavior for Germanic languages.
Compare post-classical Latin defenestratio (1620 or earlier, although the author claims to be coining the word). Compare also Middle French, French défenestrer to throw out of a window (1564), and German Fenstersturz (1626 or earlier in this sense; lit. ‘act of throwing from a window’; also more fully Prager Fenstersturz), the usual German name for the 1618 event.
Wiktionary actually lists both words as sorta-cognates (under ‘etymology’). However, Wiktionary has a habit of not listing any dates. But, Trésor de la langue française informatisé says that the 1564 source uses the word in the meaning of removing windows of a house — while also noting that the French-root ‘défenêtrer’ should be used for this meaning instead of the Latin ‘défenestrer’.
In the typical blunt German manner, ‘Fenstersturz’ is simply composed of ‘window’+‘fall’.
Ackshually it’s from Neo-Latin ‘fenestra’ meaning ‘window’, specifically coined in 1620, presumably as ‘defenestratio’:
‘Fenster’ was borrowed from Latin as ‘*fenestr’ way back in the times of Proto-West Germanic. Which, to my understanding, is a somewhat unusual behavior for Germanic languages.
Interesting, the OED adds this:
“Defenestration, N., Etymology.” Oxford English Dictionary, Oxford UP, March 2025, https://doi.org/10.1093/OED/9213494086.
Wiktionary actually lists both words as sorta-cognates (under ‘etymology’). However, Wiktionary has a habit of not listing any dates. But, Trésor de la langue française informatisé says that the 1564 source uses the word in the meaning of removing windows of a house — while also noting that the French-root ‘défenêtrer’ should be used for this meaning instead of the Latin ‘défenestrer’.
In the typical blunt German manner, ‘Fenstersturz’ is simply composed of ‘window’+‘fall’.