c. 1400, "fleshy part of a fruit or plant," from Latin pulpa "animal or plant pulp; pith of wood," earlier *pelpa, perhaps from the same root as pulvis "dust," pollen "fine flour" (see pollen); extended to other similar substances by early 15c. The adjective meaning "sensational" is from pulp magazine (1931), so called from pulp in sense of "type of rough paper used in cheaply made magazines and books" (1727). As a genre name, pulp fiction attested by 1943 (pulp writer "writer of pulp fiction" was in use by 1939). The opposite adjective in reference to magazines was slick.
1660s "reduce to pulp" (implied in pulping), from pulp (n.). As "to remove the pulp from," from 1791. Related: Pulped.