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]