ordovician period Definition

ordovician, geological period, silurian period, geological time, time, civil time, pythiad, zonetime, hadean time, geological era, timist, untime, timeling, period of time, civil year, time of departure, mean solar day, equitemporaneous, time of year, new york minute, unit of time, solar day, sidereal day, epoch, time unit, sidereal year, in good time, time bill, period, timeful, interlapse, dureless, sidereal time, cenozoic era, permian period, universal time, father time, triduan, ephemeris time, foretime, horometry, mesozoic era, cosmic time, terdiurnal, clock up, index fossil, centuriator, nychthemeron, periodoscope, buy time, ante meridiem, bimestrial, antichronism, victory day, leap second, anomalistic year, archaeozoic, academic term, time exposure, biological time, autochronograph, periodic event, noematachograph, undern, therebefore, secle, preeternity, present perfect, day, musical time, tropical year, prenominate, zeptosecond, isocryme, circumduce, relaxation time, alaska standard time, elapse, time signal, diurnation, exponential distribution, launch window, big hand, irrevoluble, while away, proemptosis, equidiurnal, umptieth, nychthemeral, international date line, horologiography, quinible, astronomical year, sabbatical year, sextan, hour, trimonthly, aftercrop, in due time, timespan,