Greek μακαριότης (makariotēs), adjective μακάριος (makarios)
Blessedness: the condition of the gods, untroubled and incorruptible, and the word Epicurus uses for the happiest human life. Principal Doctrine 1 opens with the "blessed and incorruptible" nature.
1. Key Texts
Quote from Epicurus, Principal Doctrine 1That which is blessed and indestructible has no troubles itself, nor does it give trouble to anyone else, so that it is not affected by feelings of anger or gratitude. For all such things imply weakness. (tr. Long & Sedley)