From Longman Dictionary of Contemporary Englishportentouspor‧ten‧tous /pɔːˈtentəs $ pɔːr-/ adjective 1 literaryIMPORTANT showing that something important is going to happen, especially something bad Recent developments are as portentous as the collapse of the Berlin Wall.2 PROUDtrying to appear important and serious a portentous film
Examples from the Corpus
portentous• Sunderland won 2-1; perhaps he will think it portentous.• Hence the portentous, and even fatuous slogan which towered each year in brightest blue above the rostrum.• That Grunwald had a good seat for all this is obviated by his talent for the portentous and gift for the unremarkable.• Neither the Realists nor the photographers were unaware of the significance of such a portentous conjunction.• The split reflected a portentous difference of approach within the Party.• Last week Karl-Marx Allee was again treated to the sounds of portentous rhetoric and polite laughter.• Such alarms reflected the Alsops' tendency to cloak their analyses in portentous terms of dread and dismay.• The captured instant often takes on meanings far more portentous than the actual event. 