A geological change in the mineral content of rock after the rock has formed

Wikipedia Word definitions in Wikipedia
In biology , epigenesis (or, in contrast to preformationism , neoformationism ) is the process by which plants, animals and fungi develop from a seed, spore or egg through a sequence of steps in which cells differentiate and organs form. Aristotle first ...

Wiktionary Word definitions in Wiktionary
n. 1 (context biology English) The theory that an organism develops by differentiation from an unstructured egg rather than by simple enlarging of something preformed. 2 (context geology English) changes in the mineral content of rock after its formation

WordNet Word definitions in WordNet
n. a geological change in the mineral content of rock after the rock has formed

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Epigenesis \Ep`i*gen"e*sis\, n. [Pref. epi- + genesis.] (Biol.) The theory of generation which holds that the germ is created entirely new, not merely expanded, by the procreative power of the parents. It is opposed to the theory of evolution , also to ...