Caliginous \Ca*lig"i*nous\, a. [L. caliginosus; cf. F. caligineux.] Affected with darkness or dimness; dark; obscure. [R.] --Blount. [1913 Webster] The caliginous regions of the air. --Hallywell. -- {Ca*lig"i*nous*ly}, adv. -- {Ca*lig"i*nous*ness}, n. [1913 Webster]