Main Entry:

lu·na·tic

Pronunciation:

\ˈlü-nə-ˌtik\

Function:

adjective

Etymology:

Middle English lunatik, from Anglo-French or Late Latin; Anglo-French lunatic, from Late Latin lunaticus, from Latin luna; from the belief that lunacy fluctuated with the phases of the moon

Date:

14th century

1 a: affected with lunacy : insane b: designed for the care of insane persons <lunatic asylum>2: wildly foolish <a lunatic idea>

— lunatic noun