1. In mainframe computing, a debugging technique that involved printing out the entire contents of the computer's core, or memory. In slang, the term refers to a person who, when asked a simple question, recites everything he or she remembers about a subject. From QUECID

2. a copy of the contents of core, produced when a process is aborted by certain kinds of internal error. It is useful to determine the nature of a program crash. From Linux Guide @FirstLinux

3. n. [common Iron Age jargon, preserved by Unix] 1. [techspeak] A copy of the contents of core, produced when a process is aborted by certain kinds of internal error. 2. By extension, used for humans passing out, vomiting, or registering extreme shock. "He dumped core. All over the floor. What a mess." "He heard about X and dumped core." 3. Occasionally used for a human rambling on pointlessly at great length; esp. in apology: "Sorry, I dumped core on you". 4. A recapitulation of knowledge (compare bits, sense 1). Hence, spewing all one knows about a topic (syn. brain dump), esp. in a lecture or answer to an exam question. "Short, concise answers are better than core dumps" (from the instructions to an exam at Columbia). See core. From Jargon Dictionary