pernicious
/pɚˈnɪʃəs/
adjective
Britannica Dictionary definition of PERNICIOUS
[more pernicious; most pernicious]
formal
:
causing great harm or damage often in a way that is not easily seen or noticed
-
More pernicious still has been the acceptance of the author's controversial ideas by the general public.
-
the pernicious effects of jealousy
-
She thinks television has a pernicious influence on our children.