originally a stronghold captured by David (the 2nd king of the Israelites); above it was built a temple and later the name extended to the whole hill; finally it became a synonym for the city of Jerusalem; "the inhabitants of Jerusalem are personified as `the daughter of Zion'"
a person who contributes to the fulfillment of a need or furtherance of an effort or purpose; "my invaluable assistant"; "they hired additional help to finish the work"