geochronologyPronunciation: /dʒiːəʊkrəˈnɒlədʒi/Definition of geochronology noun [mass noun] the branch of geology concerned with the dating of rock formations and geological events. Derivatives geochronologicalPronunciation: /-krɒnəˈlɒdʒɪk(ə)l/ adjective geochronologist noun geochronology in other Oxford dictionaries Definition of geochronology in the US English dictionary