-e·sis \ˈēsə̇s, _əsə̇s\noun suffix (plural-eses \ˈē(ˌ)sēz, _əˌsēz\) Etymology: Middle English, from Old English, from Latin, from Greek -esis, -ēsis, from -e-, -ē-, derivational element attached to certain verbs + -sis, feminine suffix of action : action : process < enuresis >