geological time - the time of the physical formation and development of the earth (especially prior to human history)time - the continuum of experience in which events pass from the future through the present to the past eon, aeon - the longest division of geological time geological period, period - a unit of geological time during which a system of rocks formed; "ganoid fishes swarmed during the earlier geological periods" geological era, era - a major division of geological time; an era is usually divided into two or more periods epoch - a unit of geological time |