Antonyms of adj concurrent

1 sense of concurrent

Sense 1
coincident, coincidental, coinciding, concurrent, co-occurrent, cooccurring, simultaneous -- (occurring or operating at the same time; "a series of coincident events")

INDIRECT (VIA synchronous) -> asynchronous -- (not synchronous; not occurring or existing at the same time or having the same period or phase)

Similarity of adj concurrent

1 sense of concurrent

Sense 1
coincident, coincidental, coinciding, concurrent, co-occurrent, cooccurring, simultaneous -- (occurring or operating at the same time; "a series of coincident events")
       => synchronous (vs. asynchronous), 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")