miasm

from WordNet (r) 3.0 (2006)

miasm
    n 1: an unwholesome atmosphere; "the novel spun a miasma of
         death and decay" [syn: {miasma}, {miasm}]
    2: unhealthy vapors rising from the ground or other sources;
       "the miasma of the marshes"; "a miasma of cigar smoke" [syn:
       {miasma}, {miasm}]

from The Collaborative International Dictionary of English v.0.48

Miasm \Mi"asm\, n. [Cf. F. miasme.]
   Miasma.
   [1913 Webster]