[ sahy-muhl-tey-nee-uhs, sim-uhl- ]

  1. existing, occurring, or operating at the same time; concurrent: simultaneous movements;simultaneous translation.

Origin of simultaneous

First recorded in 1650–60; from Latin simul “together” (see similar) + (instan)taneous

Other words for simultaneous

Other words from simultaneous

  • si·mul·ta·ne·ous·ly, adverb
  • si·mul·ta·ne·i·ty [sahy-muhl-tuh-nee-i-tee, -ney-, sim-uhl-], /ˌsaɪ məl təˈni ɪ ti, -ˈneɪ-, ˌsɪm əl-/, si·mul·ta·ne·ous·ness, noun
  • non·si·mul·ta·ne·ous, adjective
  • un·si·mul·ta·ne·ous, adjective
  • un·si·mul·ta·ne·ous·ness, noun

Words Nearby simultaneous Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use simultaneous in a sentence

British Dictionary definitions for simultaneous


/ (ˌsɪməlˈteɪnɪəs, US ˌsaɪməlˈteɪnɪəs) /

  1. occurring, existing, or operating at the same time; concurrent

  1. chess a display in which one player plays a number of opponents at once, walking from board to board: Sometimes shortened to: simul

Origin of simultaneous

C17: formed on the model of instantaneous from Latin simul at the same time, together

Derived forms of simultaneous

  • simultaneously, adverb
  • simultaneousness or simultaneity (ˌsɪməltəˈniːɪtɪ, US ˌsaɪməltəˈniːɪtɪ), noun

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