geological period, period

epoch, heyday, advent, millennium, nineties, millenium, modern, throwback, dawning, seventies, sixties, yesteryear, eighties, atomic age, aughts, paradigm, revolution, dark ages, reign, interregnum, decade, anachronism, halcyon, dynasty, legacy, beginnings, renaissance, weimar republic, usher, yore, redux, generation, ascendence, postwar, postbellum, perestroika, industrial revolution, incarnation, vestiges, wwii, heralds, holdover, rebirth, proto, relic, vogue, history, forerunner, headiest, annals, apotheosis, utopian socialism, renascent, industrialism, meiji restoration, great proletarian cultural revolution, emergence, gerontocracy, antediluvian, wartimes, wwi, babylonian captivity, red scare, utopia, antithesis, mindset, mentality, glasnost, franklin roosevelt, nostalgists, ptolemaic, mccarthyism, reminiscent, phonographs, ism, millennial, sovietism, clement attlee, boom, birth pangs, epitome, century, ascendancy, zeitgeist, qing dynasty, neo, lexicon, dwight eisenhower, inevitability, harken, apogee, style, zenith, royalism, ancien regime, cultural revolution, paean, tenure, dictatorship, regime, twilight, hearkening, eras, period, age, civilization, episteme, decades, times, ideology, civilisation, convention, generations, marx, antebellum, eighteenthcentury, prerevolutionary, thecentury, victorian, 1950s, georgian, prewar, bellum, edwardian, nineteenthcentury, agrarian, cistercian, mainstream, medieval, carolingian

age of mammals, age of reptiles, archaeozoic, archaeozoic era, archeozoic, archeozoic era, cenozoic, cenozoic era, christian era, common era, day, historic period, mesozoic, mesozoic era, paleozoic, paleozoic era, preoterozoic era, proterozoic

., ad, aeonian, age, anno domini, archaeozoic, archeozoic, bc, before christ, caliphate, carboniferous, celtic, celtic language, cretaceous, day, departed, dinosaur, edwardian, ending, eonian, epoch-making, epochal, ethos, geological era, golden, guadalajara, hegira, hejira, historic period, joseph lincoln steffens, lincoln steffens, ludi saeculares, macroevolution, modern, proterozoic, secular games, steffens, ushering in, victoriana, victorian age, year of grace

aeon, eon

amount of time, geological time, geologic time, period of time, time period