- Of the nature of a portent; containing portents;
foreshadowing, esp. foreshadowing ill; ominous. - Hence: Monstrous; prodigious; wonderful; dreadful; as,
a beast of portentous size.
Meaning of 'portentous' (Princeton's WordNet)
1 . portentous
[ s]
Meaning (1): - puffed up with vanity
Example in sentence:
a grandiloquent and boastful manner;
a pompous speech;
overblown oratory;
pseudo-scientific gobbledygook and pontifical hooey
Meaning (2): - of momentous or ominous significance
Example in sentence:
a prodigious vision;
such a portentous...monster raised all my curiosity