Pancreatic means “of the pancreas” or “coming from the pancreas.” That gland, near your stomach, makes insulin and a liquid that helps your body use food. Doctors talk about pancreatic juice, a pancreatic enzyme, pancreatic disease, pancreatic cancer. You almost never use the word outside medicine or biology class. It does not name a different body part; it only points back to that one gland. In ordinary talk people are more likely to say “of the pancreas” or just name the illness. Though actually, once you know pancreas, this is the regular “belonging-to” form, not a new idea.