My I-Search Word: Mercy

The reason that I chose the word "mercy" is because of Toni Morrison's A Mercy, one of my favorite books of all time. The word "mercy" appears in Morrison's novel in the excerpt: "It was not a miracle. Bestowed by G-d. It was a mercy. Offered by a human." This very passage is one of the reasons that I love the novel so much. It seems to imply that a "mercy" is the human form of a miracle, which is, by Morrison's definition, divine. (This made me realize that "miracle" would've been an interesting word choice as well). But is Morrison's use of "mercy" always what the word means? When I think of "mercy", this passage comes to mind first, and then I think of the childhood game "mercy" where two players try to hurt each other's hands until one of them declares defeat by yelling "Mercy!" In this context, the word signifies giving up; this definition certainly does not seem to correspond to Morrison's definition of a form of a miracle. I am really curious to research how one word can have such seemingly different definitions or usages that are actually related. I want to know if the word was always used in these two different ways or if one branched out of the other.