loony
UK[ˈluːni]US[ˈluːni]
adj
Crazy or silly
n
A crazy or silly person
Etymology
The word "loony" is a 19th-century informal shortening of "lunatic." Its ultimate origin lies in the Latin lunaticus, meaning "moonstruck," derived from luna (moon). This reflects the ancient belief that phases of the moon, particularly the full moon, could trigger insanity or erratic behavior. Over time, "lunatic" entered English via Old French, and its colloquial abbreviation "loony" evolved to describe not clinical madness but general foolishness or eccentricity, softening and broadening the original association with the moon's influence.
Analysis
This word is a simplex. It is a clipping of the word "lunatic," which itself originates from the Latin lunaticus, meaning "moonstruck," from luna (moon).
Examples
That's a completely loony idea.
He was acting like a total loony at the party.
The plot of the movie is delightfully loony.