The word church is probably derived from the Greek kuriakon (i.e., “the Lord’s house”), which was used by ancient authors for the place of worship.
In the New Testament, it is the translation of the Greek word ecclesia, which is synonymous with the Hebrew kahal of the Old Testament, both words meaning simply an assembly, the character of which can only be known from the connection in which the word is found. There is no clear instance of its being used for a place of meeting or of worship, although in post-apostolic times it early received this meaning. Nor is this word ever used to denote the inhabitants of a country united in the same profession, as when we say the “Church of England,” the “Church of Scotland,” etc.
Easton’s Bible Dictionary: Church