synchronal

accessory adjuvant attendant attending belonging coefficient coeval collateral complementary contemporary coordinate corollary fellow incident joint satellite

agreeing ancillary associated with associative coetaneous coexistent coincident coincidental concordant concurrent conjoined conjoined with connected contemporaneous coterminous coupled with in tempo in time isochronal isochronous synchronous synergetic synergistic

accidental chance unrelated

circumstantial coeval coexisting coincident concerted concomitant contemporaneous in sync incidental parallel synchronous

disagreeing divergent nonconcurrent

attendant coeval concomitant current present

accompanying associated coetaneous coexistent coexisting coincident concurrent connected contemporaneous linked related simultaneous synchronic synchronous

absent past

future old old-fashioned preceding succeeding

concurrent

accompanying agreeing at the same time coetaneous coeval coexistent coexisting coincident coinciding concurring contemporaneous contemporary dead heat in sync synchronic synchronous with the beat

asynchronous different divided following preceding separate