More from this author. 1  Largest World Cities: 2014. 2  World Urban Areas Population and Density: A 2012 Update. 3  Largest Cities in the World: 2016. 4  Largest 1,000 Cities on Earth: World Urban Areas: 2015 Edition. 5  The Costs of Smart Growth Revisited: A 40 Year Perspective.
Definition of fossil. 1  1 : a remnant, impression, or trace of an organism of past geologic ages that has been preserved in the earth's crust â compare living fossil. 2  2a : a person whose views are outmoded : fogyb : something (such as a theory) that has become rigidly fixed.
fossil. n. 1. (Palaeontology). a. a relic, remnant, or representation of an organism that existed in a past geological age, or of the activity of such an organism, occurring in the form of mineralized bones, shells, etc, as casts, impressions, and moulds, and as frozen perfectly preserved organisms. b. (as modifier): fossil insects. 2.