preview

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An advance showing, as of a movie or art exhibition, to which a selected audience is invited before public presentation begins.
• noun An advance viewing or exhibition, especially the presentation of several scenes advertising a forthcoming movie; a trailer.
• noun An introductory or preliminary message, sample, or overview; a foretaste.
• transitive verb To view or exhibit in advance.
• transitive verb To provide a preliminary sample or overview of.

from The Century Dictionary.

• To see beforehand.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A foretaste of something.
• noun colloquial An advance showing of a film, exhibition etc.
• noun Something seen in advance.
• verb To show or watch something, or part of it, before it is complete.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb 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
• noun an advertisement consisting of short scenes from a motion picture that will appear in the near future