Synonyms for Asynchronous (same or very similar meaning)
WordNet sense 1 (not occurring together):
nonsynchronous, unsynchronized, unsynchronousWordNet sense 2 (chronologically misplaced):
anachronistic, anachronous, anachronicWordNet sense 3 ((of taxa) occurring in different geologic times):
allochronicFrom the ODE community, based on WordNetadd/edit