millennia

noun

1. (form-of, plural)plural of millennium
2. (nonstandard)a single period of 1000 years, a millennium

   “Could its existence mean the ancient Greeks knew the Earth moved round the Sun more than a millennia before Copernicus brought it to the world in the sixteenth century?”

   “In ancient Egypt, at the turn of the first millennia, animal mummies were produced in vast numbers as offerings to the pantheon of gods.”