How Well Do You Know English Slang?
c.1600, "to see beforehand," from pre- + view (v.). Meaning "to show (a film, etc.) before its public opening" is from 1928. Related: Previewed; previewing.
"a foretaste," 1880, from preview (v.); specifically "a showing of a book, film, etc. before public release" from 1920.