Plural of ambience; the characteristic atmosphere or mood of a place or situation.
From French ambiance (surroundings), derived from Latin ambiens (going around). The word entered English in the mid-20th century and ambiences is simply its regular plural form.
Ambience is one of those French loanwords that English adopted relatively recently—it became popular in the 1950s among designers and architects who wanted a fancier way to say 'atmosphere' or 'mood.'
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