- synchronous, synchronal, synchronic - occurring or existing at the same time or having the same period or phase; "recovery was synchronous with therapy"- Jour.A.M.A.; "a synchronous set of clocks"; "the synchronous action of a bird's wings in flight"; "synchronous oscillations"
- synchronic, descriptive - concerned with phenomena (especially language) at a particular period without considering historical antecedents; "synchronic linguistics"; "descriptive linguistics"
Antonyms: diachronic, historical
- synchronic - (of taxa) occurring in the same period of geological time
Antonym: asynchronous (indirect, via synchronous)