Synonyms for pernicious

modified

pernicious applies to that which does great harm by insidiously undermining or weakening pernicious anemia, a pernicious dogma; baneful implies a harming by or as if by poisoning a baneful superstition; noxious refers to something that is injurious to physical or mental health noxious fumes; deleterious implies slower, less irreparable injury to the health the deleterious effects of an unbalanced diet; detrimental implies a causing of damage, loss, or disadvantage to something specified the speech was detrimental to our cause