Pestiferous, a.
Etymology: [L. pestiferus, pestifer; pestis pest + ferre to bear: cf. F. pestifère.]
1. Pest-bearing; pestilential; noxious to health; malignant; infectious; contagious; as, pestiferous bodies. "Poor, pestiferous creatures begging alms." Evelyn. "Unwholesome and pestiferous occupations." Burke.
2. Noxious to peace, to morals, or to society; vicious; hurtful; destructive; as, a pestiferous demagogue. Pestiferous reports of men very nobly held. Shak.
Shades of meaning
Fernald has no entry of its own for pestiferous; he lists it under pernicious.
He lists it without comment; the entries above explain its neighbors.