lightproof

from WordNet (r) 3.0 (2006)

lightproof
    adj 1: not penetrable by light; "lightproof containers" [syn:
           {lightproof}, {light-tight}]

from Moby Thesaurus II by Grady Ward, 1.0

30 Moby Thesaurus words for "lightproof":
      airtight, close, compact, dustproof, dusttight, fast, firm,
      gasproof, gastight, hermetic, hermetically sealed, lighttight,
      oilproof, oiltight, rainproof, raintight, sealed, shut fast,
      smokeproof, smoketight, snug, staunch, stormproof, stormtight,
      tight, water-repellant, waterproof, watertight, windproof,
      windtight