[1] : The Collaborative International Dictionary of English v.0.48

caliginous \calig"inous\, a. l. caliginosus; cf. f.
   caligineux.
   affected with darkness or dimness; dark; obscure. r.
   --blount.
   1913 webster

         the caliginous regions of the air.       --hallywell.
   -- calig"inously, adv. -- calig"inousness, n.
   1913 webster
see also:
calig"inously calig"inousness 

[2] : WordNet (r) 2.0

caliginous
     adj : dark and misty and gloomy

Caliginous >> C Words
Caliginous, definition of term: Caliginous
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