PORTENTOUS

adj. 1 ominous, threatening, momentous, sinister, fateful, alarming, menacing, foreboding, ill-omened, inauspicious, unfavourable, ill-starred, ill-fated, star-crossed, lowering or louring, gloomy, unpromising, unpropitious Precisely at midnight they appeared with the most portentous news 2 extraordinary, amazing, astonishing, astounding, prodigious, awesome, awe-inspiring, remarkable, marvellous, phenomenal, fabulous, fantastic, mind-boggling, wondrous, miraculous The coronation of a British monarch is truly a portentous event