placidity

placid +‎ -ity, from Latin placiditās (“mildness, placidity”).

• (US) IPA^(key): /pləˈsɪd.ə.ti/

placidity (usually uncountable, plural placidities)

1. The state of being placid; peacefulness.
   • 1815, Jane Austen, Emma, volume III, chapter 10:

     And how could she bear such behaviour! Composure with a witness! to look on, while repeated attentions were offering to another woman, before her face, and not resent it.—That is a degree of placidity, which I can neither comprehend nor respect.

   • 1838, [Letitia Elizabeth] Landon (indicated as editor), chapter XVI, in Duty and Inclination: […], volume III, London: Henry Colburn, […], →OCLC, page 207:

     Thus, in rapid succession, passed the thoughts of Rosilia, who, endeavouring to assume placidity, once more essayed to express her thanks to Mrs. Melbourne for her kind attentions, […]

   • 1899 February, Joseph Conrad, “The Heart of Darkness”, in Blackwood’s Edinburgh Magazine, volume CLXV, number M, New York, N.Y.: The Leonard Scott Publishing Company, […], →OCLC, part I, page 200:

     The swift and indifferent placidity of that look troubled me.

• (state of being placid): composure, peacefulness, serenity

• placid
• placidly
• placidness