Pulp was a term for the fleshy, seed-containing portion of a fruit. The term could also describe any material that was semi-solid, soft, and wet.
To pulp a publication was to destroy it by turning it back into paper pulp. In 1957, Mister Stone an entire issue of Incredible Tales of Scientific Wonder for being below their usual high standards (containing Benny Russell's stories about a African-American space station commander). In a fit of furor, Russell noted that "You can pulp a story but you cannot destroy an idea." (DS9: "Far Beyond the Stars")
In 2254, Christopher Pike fantasized about beating the Talosians' heads to a pulp and other violent, hate-filled thoughts to block out their telepathy. (TOS: "The Cage", "The Menagerie, Part I")
In 2371, Deral showed Jadzia Dax the secret to eating a type of fruit, by removing the pulp and eating the flesh close to the rind. (DS9: "Meridian")