Of momentous or ominous significance. / Ominously prophetic. / Puffed up with vanity.

In an ominous manner. / In a pompous manner.

The quality of being portentous

Something that portends an event about to occur, especially an unfortunate or evil event; an omen. / A portending; significance / Something regarded as portentous; a marvel; prodigy.

plural of portent

portentous; presaging or foreshadowing

plural of portention

portent; omen