Both Uses of

pernicious

in

Henry VIII

All the commons Hate him perniciously, and, o' my conscience, Wish him ten fathom deep.†
Scene 2.1 *

My good Lord Archbishop, I'm very sorry To sit here at this present, and behold That chair stand empty; but we all are men, In our own natures frail, and capable Of our flesh; few are angels: out of which frailty And want of wisdom, you, that best should teach us, Have misdemean'd yourself, and not a little, Toward the King first, then his laws, in filling The whole realm, by your teaching and your chaplains, For so we are inform'd, with new opinions Divers and dangerous, which are heresies And, not reform'd, may prove pernicious.†
Scene 5.3

Definition:

harmful or something spreading harm -- especially in a gradual or subtle way