Miracle: "An event brought about by a special act of God. There is much disagreement about the definition beyond this minimum. Some thinkers argue that a miracle must involve an exception to the laws of nature or (perhaps alternatively) involve some event that exceeds the natural powers or capacities of natural things. Others insist that a miracle is recognizable primarily by its revelatory power as a sign that shows something about God or God's purposes and that such events do not have to be scientifically inexplicable. Since David Hume's famous attack on miracles, the possibility of miracles and the kind of evidence needed for belief in miracles has been subject to debate. Traditional 'apologetics viewed miracles as important confirmation or certification that a prophet or apostle was genuinely sent by God."
Evans, C. (2002) Pocket Dictionary of Apologetics & Philosophy of Religion. Downers Grove, IL: InterVarsity Press.