serein \ suh-RAN \, noun;
1.Meteorology . fine rain falling after sunset from a sky in which no clouds are visible.
Quotes:
The sky was clear, but a serein drizzled onto them.
-- China Miéville, "Iron Council," 2004
Serein is the falling evening dew, which results from the general chilling of the stratum of air nearest the earth's surface after sundown.
-- John William Moore, "Meteorology: Practical and Applied," 1894
Origin:
Serein is a French loanword with roots in the Latin term sērus meaning "late." It entered English in the mid-1800s.
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