Websters online gives the etymology of "quark" as "coined by Murray Gell-Mann"

"Quark" is what the German's call a fresh cheese that resembles guano. Colloquially, "Quark" means "nonesense." Unnamed sources tell me its usage in physics originates in Joyce's Ulysses. Of man, bird, and droppings, "Two quarks for Mr. Marks." The essence of matter is birdsh_t.