ataraxy

noun2

1. •
   Ataraxia; freedom from mental disturbance; imperturbability, dogged indifference.

   • When the Pyrrhonians say, that ataraxy is the chiefe felicitie, which is the immobilitie of judgement, their meaning is not to speake it affirmatively[…]. — 1603
2. •
   State of psychological calm and tranquility, absence of discomfort, or metabolical inactivity.