The Collaborative International Dictionary of English v.0.48:

cinema \cinema\ n.
   1. the art of creating motion pictures; as, this story would
      be good cinema; -- often used in the phrase the cinema.

   Syn: the film.
        [WordNet 1.5 +PJC]

   2. a theater where motion pictures are shown.

   Syn: movie theater, movie theatre, movie house, picture
        palace.
        [WordNet 1.5]

   3. same as motion picture. [Chiefly Brit.]
      [PJC] Cinematic

WordNet (r) 3.0 (2006):

cinema
    n 1: a medium that disseminates moving pictures; "theater pieces
         transferred to celluloid"; "this story would be good
         cinema"; "film coverage of sporting events" [syn: film,
         cinema, celluloid]
    2: a theater where films are shown [syn: cinema, movie
       theater, movie theatre, movie house, picture palace]

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "cinema":
   3-D, Cinemascope, Cinerama, Technicolor, Western, animated cartoon,
   art film, black-and-white film, cartoon, chiller, cine,
   cinema verite, cinematograph, color film, creepie, documentary,
   documentary film, drive-in, educational film, feature, film, flick,
   flicker, horror picture, horse opera, kinematograph,
   motion picture, motion-picture show, movie, movie theater,
   moving picture, moving-picture theater, newsreel, nickelodeon,
   nouvelle vague, nudie, photodrama, photoplay, picture,
   picture house, picture palace, picture show, pornographic film,
   preview, short, show, silent, silent film, skin flick,
   sneak preview, spaghetti Western, talkie, talking picture,
   the cinema, the movies, the pictures, the screen,
   the silver screen, thriller, trailer, underground film