Back to explorer

entry

simultaneously

/ˌsɪməlˈteɪnɪəsli/; /ˌsaɪməlˈteɪnɪəsli/

At the same time or on the same occasion

From Medieval Latin, from Latin simultaneous (Together or at the same time).

adverb
simultaneous
Latin
simul
Together; at the same time
Medieval Latin
simultaneus
Occurring at the same time; perhaps influenced by extended simultim
English, 1650s
simultaneous
Existing, occurring, or appearing at the same time
Modern English
simultaneously
Adverb formed with English -ly
Modern English
simultaneously

Picture two events unfolding side by side: that is the central image behind Latin simul, meaning “together” or “at the same time.” Medieval Latin turned it into simultaneus, and English adopted simultaneous in the 1650s for things happening in parallel. The same Latin family is connected with similis, “like” or “resembling,” which also gave English similar and similitude—so “at the same time” and “alike” are distant linguistic cousins. Mark Twain later played with the adjective and back-formed the verb simultane, meaning to do one thing at the same time as another. Add the ordinary English adverbial ending -ly, and simultaneously becomes a grammatical multitasker: one word carrying two actions in step.

§