Answer: apophysis

AnswerCrossword Clue
apophysisA small offshoot extending from an igneous intrusion into the surrounding rock
apophysisA natural protuberance from a bone, or inside the shell or exoskeleton of a sea urchin or insect, for the attachment of muscles
apophysisan expanded or projecting part of an organism, esp of bone
apophysisA swelling at the base of the sporangium in some mosses