• (British) IPA: /sɪm.əlˈteɪ̯n.i.əs/
• (America) IPA: /ˌsaɪ̯m.əlˈteɪ̯n.i.əs/

simultaneous (not comparable)

1. Happening at the same moment.
   • 1992, Rudolf M[athias] Schuster, The Hepaticae and Anthocerotae of North America: East of the Hundredth Meridian, volume V, New York, N.Y.: Columbia University Press, →ISBN, page 3-4:

     As with the Lejeuneaceae, this pattern of massive speciation appears to be correlated with the Cretaceous explosion of the angiosperms and the simultaneous creation of a host of new microenvironments, differing in humidity, light intensity, texture, etc.

2. (mathematics, of a set of equations) To be solved for the same values of variables.

• (happening at the same moment) sequential

• French: simultané
• German: gleichzeitig, simultan
• Italian: simultaneo
• Portuguese: simultâneo
• Russian: одновре́ме́нный
• Spanish: simultáneo