1. 
[syn: infective, morbific, pathogenic]
The Collaborative International Dictionary of English v.0.48:
Morbific \Mor*bif"ic\, Morbifical \Mor*bif"ic*al\, a. [L. morbus
   disease + -ficare (in comp.) to make: cf. F. morbifique. See
   -fy.]
   Causing disease; generating a sickly state; as, a morbific
   matter.
   [1913 Webster]
WordNet (r) 3.0 (2006):
morbific
    adj 1: able to cause disease; "infective agents"; "pathogenic
           bacteria" [syn: infective, morbific, pathogenic]
Moby Thesaurus II by Grady Ward, 1.0:
21 Moby Thesaurus words for "morbific":
   bad, bad for, contaminated, foul, harmful, injurious, insalubrious,
   insanitary, noisome, noxious, pathogenic, peccant, pestiferous,
   polluted, septic, tainted, unhealthful, unhealthy, unhygienic,
   unsanitary, unwholesome