(a.) Great in size, amount, or excellence; awe-inspiring; fitted to excite fear or terror; such as may astonish or terrify by its magnitude, force, or violence; terrible; dreadful; as, a tremendous wind; a tremendous shower; a tremendous shock or fall.

Atlantean Brobdingnagian Cyclopean Gargantuan Herculean Homeric abysmal amazing amplitudinous appalling astounding astronomic astronomical awe-inspiring awesome awful boundless bulky colossal cosmic cracking dire direful divine dread dreaded dreadful elephantine enormous epic exquisite extensive fantastic fell flabbergasting formidable frightful galactic ghastly ghoulish giant giantlike gigantic gilt-edged glorious golden grim grisly gruesome heavenly heroic hideous horrendous horrible horrid horrific horrifying huge immeasurable immense infinite jumbo king-size large macabre magnificent mammoth marvelous massive massy mighty monster monstrous monumental morbid mortal mountainous outsize overgrown prodigious profound redoubtable schrecklich sensational shocking sizable spacious splendid splendiferous sterling stupendous super superb supereminent superexcellent superfine terrible terrific titanic towering vast voluminous weighty wonderful