simultaneous

The word 'simultaneous' is a modern Latin formation, coined in the 17th century from the Latin adverb simul, meaning "at the same time." This root simul is thought to derive from the Proto-Indo-European root sem-, meaning "one, together," which is also the source of English words like 'same' and 'similar.' The element -tane- was appended, likely influenced by or extracted from the Latin momentaneus (momentary), to create a new adjective specifying concurrence in time. Thus, the literal construction "characterized by being at the same time" evolved directly into its modern abstract meaning describing events that coincide.

Structure: simul (same) + tane (time) + ous (adjective suffix) - simul: From Latin simul, meaning "at the same time, together." It functions as the core root indicating sameness or concurrence. - tane: A variant of the Latin root -tan-, related to tempus (time). It functions to specify the domain (time) in which the sameness occurs. - ous: A suffix of Latin origin (-osus) used to form adjectives meaning "full of" or "characterized by."