What is the difference between a chiliad and a millennium?
What's the difference between a chiliad and a millennium? Not much: both are a period of 1000 years. While millennium is more widely used, chiliad is actually older. Chiliad first appeared in the late 1500s and was originally used to mean "a group of 1000," as in "a chiliad of arrows"; millennium didn't make its way into written English until some decades later, in the early 1600s. Not surprisingly, both words trace back to roots that mean "thousand." Millennium comes from Latin mille, and chiliad is a descendant of Greek chilioi.