[mon.strous] adj (15c) 1 obs: strange, unnatural
2: having extraordinary often overwhelming size: gigantic 3 a: having the qualities or appearance of a monster b obs: teeming with monsters
4. a: extraordinarily ugly or vicious: horrible b: shockingly wrong or ridiculous
5: deviating greatly from the natural form or character: abnormal
6: very great--used as an intensive -- mon.strous.ly adv -- mon.strous.ness n syn monstrous, prodigious, tremendous, stupendous mean extremely impressive. monstrous implies a departure from the normal (as in size, form, or character) and often carries suggestions of deformity, ugliness, or fabulousness "the monstrous waste of the project". prodigious suggests a marvelousness exceeding belief, usu. in something felt as going far beyond a previous maximum (as of goodness, greatness, intensity, or size) "made a prodigious effort and rolled the stone aside". tremendous may imply a power to terrify or inspire awe "the tremendous roar of the cataract". stupendous implies a power to stun or astound, usu. because of size, numbers, complexity, or greatness beyond description "a stupendous volcanic eruption".