ENGLISH
REFERENCE

simultaneous

adj.
B2 Upper Intermediate US //ˌsaɪməɫˈteɪniəs// UK //sˌɪməltˈeɪniəs// si·mul·ta·ne·ous

adj. happening at the exact same time. You use this word when two or more events occur together, not just around the same period.

adj. occurring, done, or existing at the same time. Often used in technical contexts to describe parallel processes or events.


SIMPLE

The two explosions happened simultaneously.

CONTEXTUAL

The orchestra played the final chord simultaneously to mark the end of the concert.

COMPLEX

The simultaneous translation allowed delegates from different countries to follow the speech without waiting for a written transcript.

Synonyms
Origin

From Medieval Latin simultaneus, from simultim (“at the same time, extended”), from Latin simul (“together, at the same time”); compare similar.

© 2026 English Reference