Entry 1 sense Webster, 1913 Geologic /jēˌ-əl-äj'-ĭk/ · Ge·o·log·ic · IPA /ˌd͡ʒi.əˈlɑdʒ.ɪk/ 01 a. Of or pertaining to geology, or the science of the earth. 1. Of or pertaining to geology, or the science of the earth.