perniciosiform

per·nic·i·os·i·form

(per-nish'ē-os'i-fōrm),
Rarely used term meaning apparently pernicious, denoting a condition or disease that appears to be pernicious or malignant.

perniciosiform

An obsolete adjective referring to that which is potentially or appears to be pernicious; either:
(1) Risky, pernurious; or
(2) Pseudomalignant.