Definition of synchronous

• 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 birds wings in flight"; "synchronous oscillations"
• (digital communication) pertaining to a transmission technique that requires a common clock signal (a timing reference) between the communicating devices in order to coordinate their transmissions