late 14c., from M.L. expressare, freq. of exprimere "represent, describe," lit. "to press out" (perhaps via an intermediary sense of something like "clay that takes form under pressure"), from ex- "out" + pressare "to press, push," from L. primere. The adj. is from L. expressus "clearly presented," pp. of exprimere; and it led to the n. (first attested 1619) meaning "special messenger." Sense of "business or system for sending money or parcels" is 1794. Related: Expressed; expresses; expressing. An express train (1841) originally ran to a certain station.