This is the word used in most English versions as a rendering of the New Testament's Greek word ekklesia. Ekklesia is the Greek equivalent of the Hebrew qahal, which means an assembly or a congregation. Neither ekklesia nor qahal means a building.
Ecclesiastical sources give the origin as kuriakon or kyriakon in Greek.
However, to accept this. Our common dictionaries, however, are honest in revealing to us the true origin. They all trace the word back to its Old English or Anglo-Saxon root, namely circe. Any encyclopaedia, or dictionary of mythology, will reveal who Circe was. Circe, daughter of the well known Sun-deity Helios.