Chiliad

chil·i·ad [kil-ee-ad]
noun

1. a group consisting of 1000 things.
2. a period of 1000 years; a millennium.

Origin

1590-1600; < Late Latin chīliad- (stem of chīlias) < Greek, equivalent to chī́li (oi) 1000 + -ad- -ad1

Synonyms

1. millenary