word-forming element meaning "nature, natural, physical," from Greek physios "nature" (from PIE root *bheue- "to be, exist, grow").
compound adjectival word-forming element of Latin origin, attached to verb stems and expressing intensity of action: "given to, inclined to, abounding in," or expressing intensity of physical or mental action, from Latin -aci- (nominative -ax, accusative -acem), noun ending used with verbal stems (see -acea), + -ous. The accompanying nouns are formed in -acity.
word-forming element meaning "new, young, recent," used in a seemingly endless number of adjectives and nouns, mostly coined since c. 1880, from Greek neos "new, young, youthful; fresh, strange; lately, just now," from PIE root *newo- (see new). In the physical sciences, caeno-, ceno- is used in the same sense. Paleo- is opposed to both.