simultum

Simultum is a Latin term used in classical and medieval Latin to denote the state or thing that is simultaneous, or the notion of simultaneity. In Latin, the root simul means together, and the suffix -tum forms an abstract noun or a neuter substantive. The adjective form is simultaneus (simultaneus in classical spelling), from which the modern English word simultaneous ultimately derives.

In linguistic and philosophical contexts, simultum is encountered as a noun indicating concurrence or occurring at the same time, and it sometimes functions within scholastic discussions of time, causation, or the co-existence of properties. Medieval authors used the term to formalize questions about temporal order, coincidence, and how different aspects relate within a single instant. It appears in Latin glossaries and treatises that address the nature of time, change, and contingency, often alongside related terms such as simulans (tending to imitate or resembling) and simulatio (simulation or feigning), which share the same root.

Modern usage of simultum is limited to historical or philological discussions of Latin vocabulary. In contemporary scholarship, the concept of simultaneity is typically expressed with the Latin adjective simultaneus or with vernacular renderings when citing Latin sources. The term remains of interest primarily to those studying Latin philology, medieval philosophy, and the linguistic history of the word root simul-.

See also: simultaneity, simultaneus, simulacrum, Latin philology. References to standard Latin dictionaries such as the Oxford Latin Dictionary or Lewis and Short may provide formal attestations and usage examples for the term and its derivatives.