say it: DOWN-fawl
downfall is a noun meaning "failure that results in a loss of position or reputation". It carries 3 recorded senses.
the falling to earth of any form of water (rain or snow or hail or sleet or mist)
a sudden decline in strength or number or importance
“the fall of the House of Hapsburg”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for downfall come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.