形容詞 portentous:

1. of momentous or ominous significance
   同義詞：prodigious
2. ominously prophetic
   同義詞：fateful, foreboding
3. puffed up with vanity- Newsweek
   同義詞：grandiloquent, overblown, pompous, pontifical

1. I see a portentous thing to come.
   我預(yù)感不祥的事情要來到了。

por.ten.tous

adj.（形容詞）
Of the nature of or constituting a portent; foreboding:
預(yù)示兇事的；不祥的：
例句：
.The present aspect of society is portentous of great change.(Edward Bellamy)
.現(xiàn)在的社會預(yù)示著重大變革的發(fā)生.(愛德華·貝拉米)

Full of unspecifiable significance; exciting wonder and awe:
怪異的；奇特的和敬畏的：
例句：
.Such a portentous and mysterious monster roused all my curiosity.(Herman Melville)
.這樣奇特而神秘的巨怪引起我強烈的興趣.(赫爾曼·梅爾維爾)

Marked by pompousness; pretentiously weighty.
自負(fù)的；自命不凡的

【引伸】
porten.tously
adv.（副詞）
porten.tousness
n.（名詞）