n.
1.a monotheistic system of beliefs and practices based on the Old Testament and the teachings of Jesus as embodied in the New Testament and emphasizing the role of Jesus as savior
2.the collective body of Christians throughout the world and history (found predominantly in Europe and the Americas and Australia)
Idiom of the Day
know (someone or something) like the back of one's hand
to know someone or something very well
I know the material for the exam like the back of my hand.