What does the word "grace" mean in the Bible?

The word "grace," as used in the Bible, usually refers to the unmerited or undeserved favor of God. However, there are examples of grace from man to man and not just from God to man.

The concept of grace is first used in Genesis 6:8 in the Old Testament. In Genesis 6:8, Noah receives "favor in the eyes of the Lord", when God realizes how awful people on Earth had become, and Noah and his family are spared the death that would befall the rest of the human race.

Another example of grace comes in Hebrews 12:15. This passage says, "See to it that no one fails to obtain the grace of God; that no "root of bitterness" springs up and causes trouble, and by it many become defiled."