simultaneous: meaning, definition, pronunciation and examples
C1Formal to neutral
Quick answer
What does “simultaneous” mean?
Happening, existing, or done at the same time.
Audio
Pronunciation
Definition
Meaning and Definition
Happening, existing, or done at the same time.
Occurring or operating in unison; concurrent. In mathematics, refers to equations satisfied by the same values of variables. In broadcasting, refers to translation or interpretation happening in real-time.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling is identical.
Connotations
Slightly more formal in everyday American English; common in British institutional language (e.g., 'simultaneous equations').
Frequency
Comparable frequency in both varieties, with a slight edge in British academic/technical writing.
Grammar
How to Use “simultaneous” in a Sentence
be simultaneous with somethingoccur simultaneous to somethinghappen simultaneous with somethingVocabulary
Collocations
Examples
Examples of “simultaneous” in a Sentence
verb
British English
- The system is designed to simultanise data entry across terminals. (rare/technical)
American English
- The software can simultanize the rendering processes. (rare/technical)
adverb
British English
- The doors opened simultaneously, revealing the grand hall.
American English
- The two alerts went off simultaneously, causing confusion.
adjective
British English
- The conference offered simultaneous interpretation in six languages.
American English
- The film had a simultaneous release in theaters and online.
Usage
Meaning in Context
Business
Used for product launches, global announcements, or coordinated actions across departments.
Academic
Common in mathematics ('simultaneous equations'), physics, and event studies.
Everyday
Describing two everyday events happening together (e.g., phone ringing and doorbell).
Technical
Crucial in computing (multitasking), telecommunications, and live broadcasting.
Vocabulary
Synonyms of “simultaneous”
Watch out
Common Mistakes When Using “simultaneous”
- Using 'simultaneous' for events that are merely close in time but not precisely concurrent.
- Misspelling as 'simultanious' or 'simultanous'.
- Using it as an adverb without '-ly' (incorrect: 'They started simultaneous'; correct: 'They started simultaneously').
FAQ
Frequently Asked Questions
No, it can describe any number of events happening at the same time (e.g., 'simultaneous translations into five languages').
They are often synonyms. 'Simultaneous' emphasizes precise coincidence in time. 'Concurrent' can sometimes imply overlapping durations or parallel existence, not just a single instant.
No, the adverbial form is 'simultaneously'. Using 'simultaneous' as an adverb is a common error.
Yes, primarily in the first vowel. British English uses /ɪ/ (as in 'sit'), while American English often uses /aɪ/ (as in 'sigh'), though the American variant with /ɪ/ is also heard.
Happening, existing, or done at the same time.
Simultaneous is usually formal to neutral in register.
Simultaneous: in British English it is pronounced /ˌsɪm.əlˈteɪ.ni.əs/, and in American English it is pronounced /ˌsaɪ.məlˈteɪ.ni.əs/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “kill two birds with one stone (conceptual, not literal synonym)”
Learning
Memory Aids
Mnemonic
Think of SIMULTANEOUS as 'SIMUL' (like 'simulate' - to mimic in time) + 'TANEOUS' (like 'instantaneous' - happening instantly). Things happening in simulated unison.
Conceptual Metaphor
TIME IS A LINE WITH POINTS; simultaneous events occupy the same point.
Practice
Quiz
Which sentence uses 'simultaneous' correctly?