rainout

or rain-out

[ reyn-out ]
/ ˈreɪnˌaʊt /

noun

a contest, performance, or the like, that has been rained out.
Also called washout. the removal of radioactive particles or other foreign substances from the atmosphere by precipitation.
Compare fallout.

Origin of rainout

1945–50, Americanism; noun use of verb phrase rain out

British Dictionary definitions for rainout

rainout
/ (ˈreɪnˌaʊt) /

noun

radioactive fallout or atmospheric pollution carried to the earth by rain