English
imperturbableness
From imperturbable + -ness.
Formed from imperturbable + -ness
Latin perturbō ‘to confuse’
Late Latin perturbabilis ‘perturbable’
Late Latin imperturbābilis
Middle English imperturbable ‘undisturbed’
English imperturbable
Today it means
noun The quality of being imperturbable.
Language periods are conventional ranges, not dates for this word.
Etymograph / imperturbableness