Mid 17th century; earliest use found in Henry More (1614–1687), philosopher, poet, and theologian. From post-classical Latin millenniummillennium + -ist. Compare French milléniste.
Definition of millennist in US English:
millennist
nounˈmɪlənɪst
rare
Millenarian.
Origin
Mid 17th century; earliest use found in Henry More (1614–1687), philosopher, poet, and theologian. From post-classical Latin millennium millennium + -ist. Compare French milléniste.