Zealots (42): Nationalist Jewish sect devoted to the overthrow of the Roman occupiers. Given to violence and terrorism. Name came from the story of Phineas in Numbers. He slayed a man and his wife with a javelin thus saving Israel from a plague. He was said to have been "zealous for his God". (Num 25:6-13)
Ziggurat (7): A tall, stepped tower of Babylonian origin, possibly meant to represent a mountain. Possibly the only physically realizable tower design using mud bricks and bitumen grout.
Zion (35): Jerusalem. (Psalm 137)
Zoroasterianism (3): Taught that there were two gods, one of light and one of darkness.