Plural of calmness; multiple instances or types of the quality of being calm and peaceful.
From 'calm' plus the noun-forming suffix '-ness' (indicating a state or quality), then pluralized with '-es'. The plural suggests different manifestations of peacefulness.
The fact that we can pluralize 'calmness' hints at something psychologists now confirm—there are different types of calm, from the peace after meditation to the focused stillness of a professional athlete to the tired acceptance of resignation.
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