Open English Wordnet
Adjectives
(a)synchronous, synchronal, synchronicoccurring 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”
(a)synchronicconcerned with phenomena (especially language) at a particular period without considering historical antecedents“synchronic linguistics”