GC: n

S: Met Office – http://www.metoffice.gov.uk/research/modelling-systems/dispersion-model (last access: 30 October 2014); http://fas.org/nuke/intro/nuke/radiation.htm (last access: 31 July 2015).

N: 1. rain-out (n.): also rain out, rainout, 1947, from rain (v.) + out (adv.).
2. Radioactive material in the atmosphere brought down by precipitation. Term and definition standardized by NATO.
3. Fallout, deposition of radioactive materials on Earth from the atmosphere. The terms rain out and snow out are sometimes used to specify such deposition during precipitant weather.

S: 1. OED – http://www.etymonline.com/index.php?term=rain-out (last access: 30 October 2014). 2. TERMIUMPLUS. 3. EncBrit – http://global.britannica.com/science/fallout-nuclear-physics (last access: 31 July 2015).

SYN:
S:

CR: acid rain, environment, nuclear energy.