imperturbability
1. [ noun ] calm and unruffled self-assurance
Synonyms: coolness phlegm imperturbableness
Examples:

"he performed with all the coolness of a veteran"

Related terms: calmness
Similar spelling:   impermeability
  imperishability
  imperfectability
  imperturbable
  imperturbableness
  impermissibility
  imperfectibility
  imperceptibility
  improbability
  impermeableness
  impregnability