Greek ἀπονία (aponia), "painlessness"; Latin indolentia (Cicero)
Because Epicurus often paired a body free from pain with a mind free from disturbance, aponia is commonly narrowed to bodily painlessness alone. But the absence of pain that Epicurus identified with pleasure covers every experience that is not painful. See The Term "Pleasure" Is The Exact Equivalent Of "Absence of Pain".
1. Key Texts
Quote from Diogenes Laertius 10.136-137Epicurus disagrees with the Cyrenaics on pleasure: they do not admit static pleasure but only the kinetic type, whereas he accepts both types, for soul and for body, as he says in his book On Choice and Avoidance and in On The End and in Book 1 of On Lives. In On Choices he speaks as follows: 'Freedom from disturbance and absence of pain are static pleasures; but joy and delight are regarded as kinetic activities.' He has a further disagreement with the Cyrenaics: they take bodily pains to be worse than mental ones, but he takes the mental ones to be worse, since the flesh is storm-tossed only in the present, but the soul in past, present and future. (tr. Long & Sedley)
Quote from Epicurus, Principal Doctrine 3The removal of all pain is the limit of the magnitude of pleasures. Wherever pleasure is present, as long as it is there, pain or distress or their combination is absent. (tr. Long & Sedley)