Simultaneity

n. occurrence at the same time

Simultaneity is the property of two events happening at the same time in at least one reference frame.The noun Simult means a supernatural coincidence, two or more divinely inspired events that occur at or near the same period of time that are related to each other in both noticeable and unnoticeable characteristics [Latin simul, at the same time; see sem-1 in Indo-European Roots + English -taneous(as in instantaneous)].
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Noun
1. happening or existing or done at the same time
(synonym) simultaneousness
(hypernym) timing
(hyponym) concurrence, coincidence, conjunction, co-occurrence

(n.)
The quality or state of being simultaneous; simultaneousness.
  

Synonyms and related words:
accompaniment, accordance, agreement, alliance, association, cahoots, co-occurrence, co-working, coaction, coincidence, collaboration, collectivity, collusion, combination, combined effort, concert, concerted action, concomitance, concomitancy, concordance, concourse, concurrence, confluence, conjunction, consilience, conspiracy, cooperation, correspondence, immediacy, immediateness, instantaneity, instantaneousness, junction, momentaneousness, momentariness, parallelism, parasitism, saprophytism, symbiosis, synchronism, synergy, togetherness, union, united action, withness