Pernicious
[adj] working or spreading in a hidden and usually injurious way; "glaucoma is an insidious disease"; "a subtle poison"
[adj] exceedingly harmful
Related Information
Related Terms
baleful, baneful, brutal, corroding, corrosive, corrupting, corruptive, counterproductive, damaging, deadly, death-bringing, deathful, deathly, deleterious, destructive, detrimental, devastating, disadvantageous, disserviceable, distressing, fatal, feral,