distorted and unnatural in shape or size; abnormal and hideous; "tales of grotesque serpents eight fathoms long that churned the seas"; "twisted into monstrous shapes"
Extraordinary in a way to excite wonder, dislike, apprehension, etc.; -- said of size, appearance, color, sound, etc.; as, a monstrous height; a monstrous ox; a monstrous story.
shockingly brutal or cruel; "murder is an atrocious crime"; "a grievous offense against morality"; "a grievous crime"; "no excess was too monstrous for them to commit"