The Collaborative International Dictionary of English v.0.48:

Gangrenous \Gan"gre*nous\, a. [Cf. F. gangr['e]neux.]
   Affected by, or produced by, gangrene; of the nature of
   gangrene.
   [1913 Webster]

WordNet (r) 3.0 (2006):

gangrenous
    adj 1: suffering from tissue death [syn: gangrenous,
           mortified]