simultaneousyoudaoicibaDictYouDict[simultaneous 词源字典]
simultaneous: see similar
[simultaneous etymology, simultaneous origin, 英语词源]
simultaneous (adj.)youdaoicibaDictYouDict
1650s, from Medieval Latin simultaneus, perhaps from simultim "at the same time," extended from Latin simul "at the same time" (see similar (adj.)), or from simul with ending abstracted from Late Latin spontaneus, where the -t- is organic. Related: Simultaneously.