Fall out

Origin of: Fall out

Fall out

In the sense of uncontrolled falling debris, following an explosion dates from c. 1945. Soon thereafter, it was being used widely in the sense of atomic or nuclear fall out. Since the mid-20th century it has also acquired a figurative meaning of generally adverse consequences. Fall out as in quarrel dates from the early 1500s. Fall out as in dismiss, a military command, dates from the early 19th century.