pernicious

Adjective

exceedingly harmful
- Synonyms
  - baneful
  - deadly
  - pestilent
- Similar to
  - noxious
- Related
  - pestilence
  - canker
  - perniciousness
  - toxicity
  - deadliness
  - lethality
working or spreading in a hidden and usually injurious way; “glaucoma is an insidious disease”; “a subtle poison”
- Synonyms
  - insidious
  - subtle
- Similar to
  - harmful
- Related
  - perniciousness
  - toxicity
  - insidiousness