What is another word for lunacy?
Pronunciation: [lˈuːnəsi] (IPA) 
Lunacy, defined as madness or irrational behavior, can be expressed with various synonyms. One can use terms such as insanity, madness, derangement, or madness to mean the same thing. At times, one might also use words such as delirium, craziness, dottiness, or mania to describe such behavior. Other possible synonyms include folly, eccentricity, absurdity, or irrationality, all of them reflecting the irrationality or illogical nature of the behavior in question. Ultimately, the synonym one chooses might depend on the context or tone one is aiming to convey, but they all capture the essence of lunacy, a state of mind characterized by erratic and often nonsensical actions or thoughts.
