The Difference Between Portentous and Pretentious

The adjective portentous means ominous or momentous, referring to a sign or prediction that something important is about to happen. Portentous can also mean pompous or self-important. (This second meaning overlaps with that of pretentious.)

The adjective pretentious means full of pretense, making excessive or unwarranted claims to be important or sophisticated.

Notice how these two words are spelled: portentous ends in -tous; pretentious ends in -tious.

Examples

• "No one spoke. But they all knew this was a portentous moment, and that this day Mister Skye would say a thing that would affect their lives." (Richard S. Wheeler, North Star. Forge, 2009)
• "The notepaper had been given her as a wedding present, embossed with a monogram of her new initials, by a Southampton aunt, boxes of it; Marcia had laughed, thinking it hideously pretentious, the essence of everything she had married Harold to escape, and used it so seldom, once the thank-you notes were written, that after twelve years it was not used up." (John Updike, Couples. Knopf, 1968)
• "Elizabeth Bishop's poetry is rarely portentous or grand, and never pretentious or grandiose." (Michael Ryan, A Difficult Grace: On Poets, Poetry, and Writing. University of Georgia Press, 2000)
• "I must have parchment! Oh, but I like writing on parchment! Each time you turn a page it rumbles like thunder. My words are so portentous--that's portentous, dear, not pretentious—it seems appropriate. Like Jove." (David Blixt, The Master of Verona. St. Martin's Press, 2007)

Usage Notes

• "[P]ortentous can be either ominous (a portentous event) or pompous (his portentous attitude); pretentious means pretending to be important. Since a pretentious person can also be pompous/portentous, there's a risk of confusion with these words. Prefer ominous or pompous to portentous. (Wynford Hicks, Quite Literally: Problem Words and How to Use Them. Routledge, 2004)
• "The main distinction is that a portentous man just might be as important as he seems, but a pretentious one cannot be as important as he claims." (Kenneth G. Wilson, The Columbia Guide to Standard American English. Columbia University Press, 1993)
• "Portentous . . . used to mean 'portending evil; ominous' and has come to mean 'pompous; self-important,' possibly because it sounds like pretentious mixed with portly—but there is poetic justice in that, since pretentiousness can be ominous." (William Safire, "On Language." The New York Times Magazine, June 7, 1981)