unprovokable

He seemed to blaze with it, – to flame up and redden with a delirious passion; and he knocked down and stamped upon the boy with a blind fury which it was really frightful to see, and which was in singular contrast with his usual unprovokable good-humor.

Oldtown Folks 1869

Eleanor was laughing; she could not see Mr. Rhys's face very well; it was somewhat bent over his papers; but the side view was of unprovokable gravity.

The Old Helmet 1864

Eleanor was laughing; she could not see Mr. Rhys's face very well; it was somewhat bent over his papers; but the side view was of unprovokable gravity.

The Old Helmet, Volume II Susan Warner 1852

There is a class of surface-skimming persons, who pronounce all things unnatural which, to a cool, unprovoked, and perhaps unprovokable mind, appear unreasonable: as if a vexed nature and exacting passions were not the most unreasonable yet most natural of all moral agents.

Confession, or, the Blind Heart; a Domestic Story William Gilmore Simms 1838

All must be vacant and blank, and the danger that stands armed with death at your elbow must continue to be totally invisible, till that moment when its vengeance is provoked or unprovokable.

Memoirs of Carwin, the Biloquist Charles Brockden Brown 1790