Wordnet 3.0
NOUN (1)
1.
photograph reduced to the size of a dot (usually for purposes of security);
WordNet (r) 3.0 (2006):
microdot
n 1: photograph reduced to the size of a dot (usually for
purposes of security)
Moby Thesaurus II by Grady Ward, 1.0:
23 Moby Thesaurus words for "microdot":
bulletin board, card, catalog card, disc, file, filing card, film,
index card, library catalog, magnetic tape, microcard, microfiche,
microfilm, motion-picture film, phonograph record, platter,
scoreboard, scorecard, scoresheet, slip, tape, ticker tape,
videotape