What are the meanings of servus and minister in ecclesiatical latin?

1. What does Servus Dei mean?
2. What is Servus Tuus Humilis?

What does Servus Dei mean?

Source: The Oxford Dictionary of the Middle Ages. A papal title meaning 'servant of God's servants'.

What is Servus Tuus Humilis?

You could thus close your letter with: humilis servus tuus in Christo [name]. This literally means, "Your humble servant in Christ." You could also substitute humillimus (="most humble").