derived from the Greek word
phusikos, φυσικός, φυσικῶς (natural; 'physical'; instinctive)
derived from the Late Greek word
phusis, φύσις (growth; growth (by germination or expansion); natural production (lineal descent); by extension, a genus or sort; figuratively, native disposition, constitution or usage)
derived from the Proto-Indo-European root
*bheuə-