The word morpheme -physis (φύσις) occurs at the ends of some anatomical names, usually of projecting parts of bones, and in some names of animals (e.g. Coelophysis). If with a Greek preposition, as in e.g. X-physis, it means "a process which sticks out in the direction X"; otherwise it means "form", "nature". It is from Greek φυσις from the verb φυω = "I bring forth", "I produce", "I make to grow".
In the name Coelophysis, the meaning as with a preposition has spread to a usage without a preposition; the name is a bahuvrihi which was probably intended to mean "having hollow processes (on its bones)".
In terms of its medical application as relating to bones, "-physis" can also mean "to grow." Specifically, as the term pertains to musculoskeletal medicine and orthopedics, "physis" refers to the region of a long bone between the epiphysis and the metaphysis, or in lay terminology, the "growth plate".