Mid 19th century; earliest use found in Philip Gosse (1810–1888), zoologist and religious writer. From pro- + ancient Greek χρόνος time + -ic, after chronic.
Definition of prochronic in US English:
prochronic
adjectiveprəʊˈkrɒnɪk
historical
Relating to a period before time began.
Origin
Mid 19th century; earliest use found in Philip Gosse (1810–1888), zoologist and religious writer. From pro- + ancient Greek χρόνος time + -ic, after chronic.