PORTENTOUS
grandiloquent, overblown, pompous, pontifical, portentous
(adjective) puffed up with vanity; “a grandiloquent and boastful manner”; “overblown oratory”; “a pompous speech”; “pseudo-scientific gobbledygook and pontifical hooey”- Newsweek
fateful, foreboding, portentous
(adjective) ominously prophetic
portentous, prodigious
(adjective) of momentous or ominous significance; “such a portentous...monster raised all my curiosity”- Herman Melville; “a prodigious vision”
Source: WordNet® 3.1
Etymology
Adjective
portentous (comparative more portentous, superlative most portentous)
Of momentous or ominous significance.
Synonyms: ominous, momentous
Ominously prophetic.
Synonyms: foreshadowing, predictive, premonitory, prognosticatory
Puffed up with vanity.
Source: Wiktionary
Por*tent"ous, a. Etym: [L. portentosus.]
1. Of the nature of a portent; containing portents; foreschadowing,
esp. foreschadowing ill; ominous.
For, I believe, they are portentous things. Shak.
Victories of strange and almost portentous splendor. Macaulay.
2. Hence: Monstrous; prodigious; wonderful; dreadful; as, a beast of
portentous size. Roscommon.
– Por*tent"ous*ly, adv.
– Por*tent"ous*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition