The story
- Latin · calque ofmillennium
- English todayyearthousand
From year + thousand, a calque of either Latin millennium (from mīllennis, “thousand-year”), or, more probably, of a Germanic-language term (most likely from German); compare Dutch jaarduizend, German Jahrtausend, Norwegian årtusen, Icelandic árþúsund, and Swedish årtusende, all meaning “millennium” and being composed of the cognates (sisterwords) of English year and thousand.
Etymology from Wiktionary, CC BY-SA 4.0.