to entertain sumptuously in company with, i.e. (middle voice or passive) to revel together; feast with; from
g4862 (σύν) and a derivative of a presumed compound of
g2095 (εὖ) and a derivative of
g2192 (ἔχω) (meaning to be in good condition, i.e. (by implication) to fare well, or feast)