Late 19th century (in an earlier sense). From ancient Greek μονόχρονος momentary, in Hellenistic Greek also in prosody (from μονο- + χρόνος time: see -chronous) + -ous.
Definition of monochronous in US English:
monochronous
adjectiveməˈnɒkrənəs
rare
Simultaneous, occurring at the same time.
Origin
Late 19th century (in an earlier sense). From ancient Greek μονόχρονος momentary, in Hellenistic Greek also in prosody (from μονο- + χρόνος time: see -chronous) + -ous.