The excessive and uncontrollable spurt of information out of a medical student. May or may not be related to the conversation (usually not).
Symptoms are exacerbated by the presence of a professor or other figure of authority.
Average Student1: Did you watch the game last night?
Gunner: "No, I was studyi... *professor comes in* Cell-derived mediators are normally sequestered in intracellular granules and can be rapidly secreted by granule exocytosis or are synthesized de novo in response to a stimulus."
Avg Student1: "WTF?"
Avg Student2: "Don't mind him, he's got gunnerrhea"