The Church

Few words translated as church in New Testament:

The meaning of "ku-ri-á-kos" is understood by its root: "kú-ri-os," which means "lord." Thus, "kuriakos" (i.e., "church") means "pertaining to the lord." It refers to something that pertains to, or belongs to, a lord.

The Greek "kuriakos" eventually came to be used in Old English form as "cirice" (kee-ree-ké), then "churche" (kerké), and eventually "church" in its traditional pronunciation. A church, then, is correctly something that "pertains to, or belongs to, a lord."

Koinonia is a Greek word whose primary meaning is “fellowship, sharing in common, communion.”

Ecclesia - called out. In few languages ecclesia is used instead of church

The Greek word "ecclesia" is correctly defined: "the called-out (ones)" [ECC = out; KALEO = call]. Thus, you can see how this word was used to indicate a civil body of select (called, elected) people