Serving to introduce something else; leading to the main subject or business; preliminary; prefatory, introducing; giving a preview or idea of, serving as a base or starting point

Plural form of preview, verb_ third person singular of preview

To view or exhibit in advance, To provide a preliminary sample or overview of, verb_ To show or watch something, or part of it, before it is complete, watch (a movie or play) before it is released to the general public, noun_ a screening for a select audience in advance of release for the general public, an advertisement consisting of short scenes from a motion picture that will appear in the near future, An advance showing, as of a movie or art exhibition, to which a selected audience is invited before public presentation begins