Synonyms of simultaneous

simultaneous

adjective

ˌsī-məl-ˈtā-nē-əs 

as in concurrent

existing or occurring at the same period of time

a simultaneous release of the movie and its soundtrack on CD

Synonyms & Similar Words

• concurrent
• synchronous
• synchronic
• coincident
• coincidental
• contemporaneous
• contemporary
• coeval
• accompanying
• concomitant
• coextensive
• coterminous
• coetaneous
• coexistent
• incident
• coexisting
• attending
• attendant

Antonyms & Near Antonyms

• asynchronous
• nonsimultaneous
• nonsynchronous
• noncontemporary

Synonym Chooser

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

Recent Examples of simultaneous

The president’s grim statements are simultaneous with the dayslong funeral for the late Ayatollah Ali Khamenei, whose coffin has been paraded across national borders accompanied by thousands of mourners. — Timothy Nerozzi, The Washington Examiner, 8 July 2026

Their simultaneous appearances come amid an ongoing rift between the brothers. — Meg Walters, InStyle, 7 July 2026

The Mass, rich in velvet and gold-trimmed vestments, chanting and incense, was livestreamed on the society’s YouTube channel, with simultaneous explanations in several languages. — Jamey Keaten, Los Angeles Times, 1 July 2026

As the possible emergence of Marburg virus disease amid an ongoing Ebola outbreak shows, the presence of one outbreak does not preclude the simultaneous circulation of another. — Krutika Kuppalli, STAT, 1 July 2026