portentous
1. [ adjective ] of momentous or ominous significance
Synonyms: prodigious
Examples:

"such a portentous...monster raised all my curiosity"- Herman Melville "a prodigious vision"

Related terms: significant
2. [ adjective ] of ominous significance
Synonyms: foreboding fateful
Related terms: prophetic
3. [ adjective ] puffed up with vanity
Synonyms: pompous overblown pontifical grandiloquent
Examples:

"a grandiloquent and boastful manner" "overblown oratory" "a pompous speech" "pseudo-scientific gobbledygook and pontifical hooey"- Newsweek

Related terms: pretentious
Similar spelling:   portentously
  portent
  Portunus
  Portnoy
  portend
  portmanteau
  Porto_Novo