Simultaneous: Definition, Usage & Examples

Meaning 1：occurring at the same time (simultaneous)

simultaneous 🔊

/ˌsɪm.əlˈteɪ.ni.əs/

adj.

It means two or more things happen at exactly the same moment.

Simultaneous action illustrated by an orchestra playing in perfect unison at the conductor's downbeat.

occurring at the same time 🔊

➕

/əˈkɜːrɪŋ æt ðə seɪm taɪm/

adj.

Describes two or more events or actions that take place at precisely the same moment.

📁 Category：Time & Dates 🔖 Level：Intermediate

📘 Details & Usage

📖 Root Explanation

From Latin 'simul' (at the same time, together) + '-taneous' (of or pertaining to).

💡 Mnemonic

Think of 'SIMULtaneous' — like 'SIMULtaneously, all clocks struck SIMUL (together) at the taneous (time)'.

📖 Example

At the international conference, the speaker's voice and the interpreter's translation were simultaneous in our headphones. 🔊 The audio of the original speech and the translated version reached our ears at the exact same instant.

🔗 Collocations

simultaneous interpretation – a translation of spoken words delivered in real-time as the speaker talks

simultaneous equations – a set of equations containing multiple variables that are all true at the same time

simultaneous release – the launch of a product or media in multiple regions at the same time

🔄 Synonyms

concurrent (adj.) – happening or existing at the same time, often used for processes or events of similar duration

synchronous (adj.) – occurring at the same rate and exactly together, often used in technical contexts like clocks or data transmission

coincident (adj.) – occurring together in time or space, often by chance rather than design

🚫 Antonyms

sequential (adj.) – forming or following a logical order or sequence in time

separate (adj.) – not joined or connected; forming or viewed as a unit apart

independent (adj.) – not connected with another or each other; separate

🌱 Derivatives

simultaneously (adv.) – at the same time

simultaneity (n.) – the quality or state of being simultaneous

simultaneousness (n.) – the fact of occurring at the same time

📖 Cultural Story

This word entered English in the 17th century from Medieval Latin 'simultaneus', built on 'simul'. It is a cornerstone of technology and science, describing perfectly synchronized events like simultaneous equations in mathematics, broadcasts, or global product launches.