portentous

adj

Etymology: Of multiple origins: * Borrowed from Latin portentōsus, from portentus (“predicted”) + -ōsus. Compare earlier portentuous (via Middle English from Latin portentuōsus). By surface analysis, portent + -ous. * Borrowed from French portentueux

1. Of momentous or ominous significance.

   “Well may it sort [be fitting] that this portentous figure comes armed through our watch, so like the King that was and is the question of these wars.”

   “It is no longer in my possession, but my memory holds almost every word of its portentous message; and again I affirm my confidence in the sanity of the man who wrote it.”

2. Ominously prophetic.
3. Puffed up with vanity.