To serve, especially at table — to wait on someone, to minister to their needs. From this verb comes diakonos (deacon/servant) and diakonia (ministry/service). Jesus radically redefined greatness by making diakoneō its measure.
Jesus' statement 'The Son of Man did not come to be served, but to serve' (Mark 10:45) turned the ancient world's power hierarchy upside down. In Greco-Roman culture, serving was demeaning — only slaves served. Jesus made it the defining act of leadership. 'Whoever wants to become great among you must be your servant' (Mark 10:43). The early church institutionalized this in the office of deacon (Acts 6), recognizing service as a spiritual calling.