PORTENTOUS Synonyms: 181 Similar and Opposite Words

Q: How does the adjective 'portentous' differ from other similar words?

The words fateful and ominous are common synonyms of portentous . While all three words mean "having a menacing or threatening aspect," portentous suggests being frighteningly big or impressive but now seldom definitely connotes forewarning of calamity. // an eerie and portentous stillness

Q: When is it sensible to use 'fateful' instead of 'portentous'?

In some situations, the words fateful and portentous are roughly equivalent. However, fateful suggests being of momentous or decisive importance. // the fateful conference that led to war

Q: When can 'ominous' be used instead of 'portentous'?

The words ominous and portentous are synonyms, but do differ in nuance. Specifically, ominous implies having a menacing, alarming character foreshadowing evil or disaster. // ominous rumblings from the volcano

portentous

adjective

pȯr-ˈten-təs

Definition of portentous next

as in ominous

being or showing a sign of evil or calamity to come an eerie and portentous stillness hung over the camp the night before the battle

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Antonyms & Near Antonyms

as in wonderful

causing wonder or astonishment in 1969 people regarded the first landing on the moon as a truly portentous event

Synonyms & Similar Words

Antonyms & Near Antonyms

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How does the adjective portentous differ from other similar words?

The words fateful and ominous are common synonyms of portentous. While all three words mean "having a menacing or threatening aspect," portentous suggests being frighteningly big or impressive but now seldom definitely connotes forewarning of calamity.

an eerie and portentous stillness

When is it sensible to use fateful instead of portentous?

In some situations, the words fateful and portentous are roughly equivalent. However, fateful suggests being of momentous or decisive importance.

the fateful conference that led to war

When can ominous be used instead of portentous?

The words ominous and portentous are synonyms, but do differ in nuance. Specifically, ominous implies having a menacing, alarming character foreshadowing evil or disaster.

ominous rumblings from the volcano

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Recent Examples of portentous Yet signs of a portentous ideological shift started to appear almost a quarter century ago, after 9/11. —

Jason Blakely, Harpers Magazine, 30 Dec. 2025 Much like the film lingers on the cold northern landscape, Obomsawin’s music is laced with portentous silences and unresolved harmonies. —

Andrew Gilbert, Mercury News, 6 Nov. 2025 Later, chugging string figures and portentous drones have the flavor of Danny Elfman and Hans Zimmer. —

Alex Ross, New Yorker, 6 Oct. 2025 In the final novel of the series, The Last Battle, the destruction of trees and dryads in Lantern Waste, a place tied to the creation of Narnia itself, is one of many portentous omens signalling the end of the world. —

Ellen Walker, JSTOR Daily, 3 Sep. 2025 See All Example Sentences for portentous

Recent Examples of Synonyms for portentous

Adjective

The biggest difference between Mythos and previous AI models was its ability to autonomously exploit vulnerabilities, an ominous new facet of the industry’s transition towards agentic models.

— Victor Tangermann, Futurism, 16 Apr. 2026
The team of astronomers credited for Apophis' discovery – David Tholen, Fabrizio Bernardi and the late Roy Tucker – were also responsible for coming up with the asteroid's ominous name.

— Eric Lagatta, USA Today, 16 Apr. 2026