1. : a natural instinct or a natural relation of human beings or other animals due to native character or condition
2. : a generalized statement of natural processes ; specifically : one of the chief generalizations of science variously conceived as imposed upon nature by the Creator, as representing an intrinsic orderliness of nature or the necessary conformity of phenomena to reason and understanding, or as the observed regular coincidences of phenomena which are ultimate data for our knowledge
3. : natural law