The word church comes from the German kirika (in modern German the church is Kirche), which derives from the Greek Kyriakon (house of the Lord) from Kyrios (ruler, Lord). It is an example of the direct Greek to German progress of many words via the Goths. From German it was also picked up by Slavic (Slavic: criky, Russian: cerkov).
In modern Greek:
a) Kyriakon: church (usually in monasteries)
b) Kyriake: Sunday
c) Kyrios: the Lord, master, man, Mr.
Kyriakon --> Kirika --> Kirche (Ger) and Church (Eng)
See the blog: English Words of no Apparent Greek Origin at: http://ewonago.blogspot.com/