The Collaborative International Dictionary of English v.0.48:

Streamer \Stream"er\, n.
   1. An ensign, flag, or pennant, which floats in the wind;
      specifically, a long, narrow, ribbonlike flag.
      [1913 Webster]

            Brave Rupert from afar appears,
            Whose waving streamers the glad general knows.
                                                  --Dryden.
      [1913 Webster]

   3. A stream or column of light shooting upward from the
      horizon, constituting one of the forms of the aurora
      borealis. --Macaulay.
      [1913 Webster]

            While overhead the North's dumb streamers shoot.
                                                  --Lowell.
      [1913 Webster]

   3. (Mining) A searcher for stream tin.
      [1913 Webster]

   4. (Journalism) a banner.
      [PJC]

WordNet (r) 3.0 (2006):

streamer
    n 1: light that streams; "streamers of flames"
    2: a newspaper headline that runs across the full page [syn:
       streamer, banner]
    3: a long flag; often tapering [syn: pennant, pennon,
       streamer, waft]
    4: long strip of cloth or paper used for decoration or
       advertising [syn: banner, streamer]

Moby Thesaurus II by Grady Ward, 1.0:

95 Moby Thesaurus words for "streamer":
   Dannebrog, Jolly Roger, Old Glory, Star-Spangled Banner,
   Stars and Stripes, Union Flag, Union Jack, X ray, actinic ray,
   actinism, and blue, atomic beam, atomic ray, banderole, banner,
   banner head, banneret, beam, beam of light, black flag,
   blue ensign, bunting, burgee, caption, coachwhip, color, colors,
   drop head, dropline, ensign, epigraph, flag, gamma ray, gleam,
   gonfalon, gonfanon, guidon, hanger, head, heading, headline,
   house flag, infrared ray, invisible radiation, jack, jump head,
   leam, legend, long pennant, merchant flag, motto, national flag,
   oriflamme, overline, patch, pencil, pendant, pennant, pennon,
   pennoncel, photon, radiation, radiorays, ray, ray of light, red,
   red ensign, ribbon, ribbon of light, royal standard, rubric,
   running head, running title, scarehead, screamer, signal flag,
   solar rays, spread, spreadhead, standard, streak, stream,
   stream of light, subhead, subheading, subtitle, superscription,
   swallowtail, title, title page, tricolor, ultraviolet ray,
   vexillum, violet ray, white