"Coffee Shop Philosopher" - Noun - This is a label given to people who enjoy sitting in coffee shops and discussing philosophy. This ties into the common stereotype of philosophers and philosophy students alike; that they are coffee addicts. Other stereotypes of addiction include: cigarettes, cigars, pipes, alchohol, boring pamphlets, and marijuana.
Another associated connotation of Coffee Shop Philosopher is their subject of discourse. Generally they deal with existential or absurd(Ref. Camus) theories or discussions. Most Coffee Shop Philosophers are not well educated in philosophy in that they are more exposed to Modern and Post-Modern philosophical works, as opposed to Ancient or Scholastic thought. This generally limits discourse to Nietzche, Camus, Sartre, Simone De Beauvoir(For the female coffeshop philosophers), and a few continentals such as Kierkagard, and Heidegger.
Some use "Coffee Shop Philosopher" as a means of slander or jeering. When used in this way it connotes a certain level of authority of the person calling someone else a Coffee Shop Philosopher. Essentially they're insinuating that the one who is a Coffee Shop Philosopher is someone who only knows the tip of the iceberg of philosophy, or again they are insinuating the connotations listed above.
"Thraysmachus: Should we invite Aristophanes to the discussion?"
"Socrates: Nah, he's a Coffee Shop Philosopher."