prodigious

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, usually 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, usually because of size, numbers, complexity, or greatness beyond description <a stupendous volcanic eruption>.