c. 1300, "a throwing," verbal noun from cast (v.). From early 15c. as "the casting of metal, the act or process of founding;" 1788 as "a metal casting, that which has been formed by running molten metal into a mold of a desired form." Theatrical sense is from 1814. Casting couch "divan in a Hollywood casting directors office," with suggestion of sexual favors in exchange for a role in a picture is by 1948.