a Greek term used by Pyrrho and Epicurus for a lucid state, characterised by freedom from worry or any other preoccupation; a state of freedom from emotional disturbance and anxiety; tranquillity; serenity.
Etymology: from Ancient Greek ἀταραξία (ataraksía), ἀ- (a-), “negative prefix” + ταράσσω (tarássō), “trouble, disturb”.