SIMULTANEOUS Synonyms: 22 Similar and Opposite Words

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

Some common synonyms of simultaneous are coeval , coincident , contemporaneous , contemporary , and synchronous . While all these words mean "existing or occurring at the same time," simultaneous implies correspondence in a moment of time. // the two shots were simultaneous

Q: When can 'coeval' be used instead of 'simultaneous'?

Although the words coeval and simultaneous have much in common, coeval refers usually to periods, ages, eras, eons. // two stars thought to be coeval

Q: In what contexts can 'coincident' take the place of 'simultaneous'?

In some situations, the words coincident and simultaneous are roughly equivalent. However, coincident is applied to events and may be used in order to avoid implication of causal relationship. // the end of World War II was coincident with a great vintage year

Q: When is it sensible to use 'contemporaneous' instead of 'simultaneous'?

The words contemporaneous and simultaneous are synonyms, but do differ in nuance. Specifically, contemporaneous is more often applied to events than to people. // contemporaneous accounts of the kidnapping

Q: Where would 'contemporary' be a reasonable alternative to 'simultaneous'?

The meanings of contemporary and simultaneous largely overlap; however, contemporary is likely to apply to people and what relates to them. // Abraham Lincoln was contemporary with Charles Darwin

Q: When might 'synchronous' be a better fit than 'simultaneous'?

The synonyms synchronous and simultaneous are sometimes interchangeable, but synchronous implies exact correspondence in time and especially in periodic intervals. // synchronous timepieces

simultaneous

adjective

ˌsī-məl-ˈtā-nē-əs

Definition of simultaneous

as in concurrent

existing or occurring at the same period of time a simultaneous release of the movie and its soundtrack on CD

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How does the adjective simultaneous differ from other similar words?

Some common synonyms of simultaneous are coeval, coincident, contemporaneous, contemporary, and synchronous. While all these words mean "existing or occurring at the same time," simultaneous implies correspondence in a moment of time.

the two shots were simultaneous

When can coeval be used instead of simultaneous?

Although the words coeval and simultaneous have much in common, coeval refers usually to periods, ages, eras, eons.

two stars thought to be coeval

In what contexts can coincident take the place of simultaneous?

In some situations, the words coincident and simultaneous are roughly equivalent. However, coincident is applied to events and may be used in order to avoid implication of causal relationship.

the end of World War II was coincident with a great vintage year

When is it sensible to use contemporaneous instead of simultaneous?

The words contemporaneous and simultaneous are synonyms, but do differ in nuance. Specifically, contemporaneous is more often applied to events than to people.

contemporaneous accounts of the kidnapping

Where would contemporary be a reasonable alternative to simultaneous?

The meanings of contemporary and simultaneous largely overlap; however, contemporary is likely to apply to people and what relates to them.

Abraham Lincoln was contemporary with Charles Darwin

When might synchronous be a better fit than simultaneous?

The synonyms synchronous and simultaneous are sometimes interchangeable, but synchronous implies exact correspondence in time and especially in periodic intervals.

synchronous timepieces

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 simultaneous It's designed to increase the sophistication of previous exercises with simultaneous air and naval drills geared toward improving joint ballistic missile defense, anti-submarine warfare, surveillance and other skills and capabilities. — ABC News, 27 Aug. 2026 And this current El Niño is especially a wildcard given the simultaneous influence of global warming due to climate pollution, which could worsen some of El Niño’s impacts. — Andrew Freedman, CNN Money, 25 Aug. 2026 The existing physical experiments and standard computational models cannot isolate these simultaneous microscale behaviors. — Mrigakshi Dixit, Interesting Engineering, 24 Aug. 2026 Kicking your tier up to Unlimited gives you 10 simultaneous high-speed connections and access to all servers. — Neil J. Rubenking, PC Magazine, 24 Aug. 2026 See All Example Sentences for simultaneous

Recent Examples of Synonyms for simultaneous

Adjective

The beta saw an all-time peak of 115,145 concurrent players on the first day.

— Jason Cohen, PC Magazine, 25 Aug. 2026
York was found guilty, according to court documents, and was sentenced to concurrent one-day jail sentences for each misdemeanor.

— Chris Biderman, Sacbee.com, 25 Aug. 2026

Definition of concurrent

Adjective

North Carolina is also home to synchronous fireflies, another bioluminescent species that lights up on land.

— Charlotte Observer, Charlotte Observer, 12 Aug. 2026
Satellites operating in sun-synchronous orbit receive steady solar energy, providing a consistent power source without depending on Earth’s electrical grid.

— Aamir Khollam, Interesting Engineering, 4 Aug. 2026

Definition of synchronous

Adjective

Accelerating human evolution coincident with the development of agriculture increased redheadedness and decreased male-pattern baldness.

— Ann Manov, Harpers Magazine, 23 June 2026
In a separate announcement, but with coincident timing, WestJet also announced a stopover plan in Calgary.

— Don Tse, Forbes.com, 23 June 2026

Definition of coincident

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simulations

simultaneous

simultaneously

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“Simultaneous.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/simultaneous. Accessed 1 Sep. 2026.

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Synonyms of simultaneous

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