an extended period of time, usu characterized by a distinctive development or by a memorable series of events
a division of geological time less than a period and greater than an age
a date or time selected as a point of reference, e.g. in astronomy
a memorable event or date; a turning point
epochal /ʹepokl/ adj
[via late Latin from Greek epochē cessation, fixed point, from epechein to pause, hold back, from epi- + echein to stay, remain the same]