<unk>  (Greek: ἀταραξία, from alpha privative ("a-", negation) and tarachē "disturbance, trouble"; hence, "unperturbedness", generally translated as "imperturbability", "equanimity", or "tranquility") is a Greek term first used in Ancient Greek philosophy by Pyrrho and subsequently Epicurus and the Stoics for a lucid state of robust equanimity characterized by ongoing freedom from distress and worry. In non-philosophical usage, the term was used to describe the ideal mental state for soldiers entering battle. Achieving<unk>  is a common goal for Pyrrhonism, Epicureanism, and Stoicism, but the role and value of<unk>  within each philosophy varies in accordance with their philosophical theories. The mental disturbances that prevent one from achieving<unk>  vary among the philosophies, and each philosophy has a different understanding as to how to achieve<unk> .
Ataraxia
Ataxia
Xanthopsia
Aspermia
Oscillopsia
Paresthesia
Photophobia
Dysmelia