downfall

Etymology

From down- + fall. In this spelling, from 16th century; spelled as two words from 13th century.

noun

1. A precipitous decline in fortune; death or rapid deterioration, as in status or wealth.
   Many economic and political reasons led to the downfall of the Roman Empire.
   The Black Cats contributed to their own downfall for the only goal when Titus Bramble, making his first appearance since Boxing Day, and Michael Turner, let Phil Jones' cross bounce across the six-yard box as [Wayne] Rooney tucked in at the back post. 13 May 2012, Alistair Magowan, “Sunderland 0 – 1 Man Utd”, in BBC Sport, archived from the original on 2019-05-09
2. The cause of such a fall; a critical blow or error.
   Orson Scott Card It is the downfall of evil, that it never sees far enough ahead.
3. An act of falling down.
   a downfall of rain

verb

1. (intransitive) To fall down; deteriorate; decline.
   … wants to make civilization his subject, he will have a hard time proceeding with the sentence unless collapse is in his active vocabulary, for he cannot say "our civilization will downfall" or "fall down." 1977, Mina P. Shaughnessy, Errors and expectations: a guide for the teacher of basic writing
   Common belief has been that in the future the number of middle managers will downfall due to empowerment and team-building. 1998, Peter Vink, Ernst A. P. Koningsveld, Steven Dhondt, Human factors in organizational design and management-VI
   It should be noted that the magnitude of satellites decreases when tuning out of degeneracy, and in the wavelength range of 1.2-1.3 pm it downfalls to the value of 10-15% of the main spike magnitude. 1998, Lithuanian physics journal
   … As goodly air as ever From lunar orb downfell— Be it by hazard, Or supervened it by arrogancy? 2008, Friedrich Wilhelm Nietzsche, Thus Spake Zarathustra