Staidness

It is difficult to say whether Mr. John Dounce's red countenance, illuminated as it was by the flickering gas-light in the window before which he paused, excited the lady's risibility, or whether a natural exuberance of animal spirits proved too much for that staidness of demeanour which the forms of society rather dictatorially prescribe.

[T]here was a staidness and sobriety about her demeanour that kept all impertinence at a distance.