[{"Bold_text": "noun", "List Items": ["a particular period of time marked by distinctive features, events, etc.:The treaty ushered in an epoch of peace and good will.Synonyms: time , era , date , age", "the beginning of a distinctive period in the history of anything:The splitting of the atom marked an epoch in scientific discovery.", "a point of time distinguished by a particular event or state of affairs; a memorable date:His coming of age was an epoch in his life.", "Geology.any of several divisions of a geologic period during which a geologic series is formed. Compare age ( def 12 ) age ( def 12 ).", "Astronomy.an arbitrarily fixed instant of time or date, usually the beginning of a century or half century, used as a reference in giving the elements of a planetary orbit or the like.the mean longitude of a planet as seen from the sun at such an instant or date.", "an arbitrarily fixed instant of time or date, usually the beginning of a century or half century, used as a reference in giving the elements of a planetary orbit or the like.", "the mean longitude of a planet as seen from the sun at such an instant or date.", "Physics.the displacement from zero at zero time of a body undergoing simple harmonic motion."]}]