| Adj. | 1. | coinciding - occurring or operating at the same time; "a series of coincident events"synchronal, synchronic, 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 bird's wings in flight"; "synchronous oscillations" | |