The adjective synchronic (composed from Greek elements syn "together" and chronos "time") means roughly "simultaneous", "at the same time". It is generally opposed to diachronic. It is used, for example, in:

• synchronic or descriptive linguistics, the study of a language at a specific point in time; as opposed to diachronic or historical linguistics which deals with how languages change over time.
• synchronic distinction or synchronic contrast, a distinction between two co-exisiting entities, e.g. between the English pronouns he and she. Opposed to a diachronic distinction, between two entities that existed in different epochs, e.g. between the archaic English verbal suffixes -eth and the modern ones -s/-es.
• synchronic process, in modern philosophy of mind, the facilitation of immediate conscious awareness in relatively brief time scales (such as 100 milliseconds).

Synchronie | همزمانی | Synchronisch versus diachronisch