asynchronous
a-syn-chro-nous
adjective
Not existing or occurring at the same time; independent of a shared clock.
"Asynchronous communication allows flexible scheduling."
Thesaurus
Synonyms: unsynchronous, serial, allochronic, nonsynchronous, anachronic, in series, nonparallel, unsynchronized, anachronistic, anachronous, unsynchronised
Antonyms: synchronal, synchronic, synchronous