Английский Этимологический словарь - fall (v.)

- O.E. feallan (class VII strong verb; past tense feoll, pp. feallen), from P.Gmc. *fallanan. Sense of "autumn" (now only in U.S.) is 1664, short for fall of the leaf (1545). Most of the figurative senses had developed in M.E. Meaning "to be reduced" (as temperature) is from 1658. Fall guy is from 1906. Fallout "radioactive particles" is from 1950.