noun, plural phy·ses [fahy-seez] /ˈfaɪ siz/.
  1. the principle of growth or change in nature.
  2. nature as the source of growth or change.
  3. something that grows, becomes, or develops.

Origin of physis

< Greek phýsis origin, natural form of a thing; akin to phŷlon race (see phylon) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018