lunacy

1. Obsolete terms for legal insanity (synset 114418644)
   is a type of: insanity - relatively permanent disorder of the mind
   same as: insaneness, madness
2. Foolish or senseless behavior (synset 100513854)
   is a type of: caper, frolic, gambol, play, romp - gay or light-hearted recreational activity for diversion or amusement
   subtypes:

   • meshugaas, mishegaas, mishegoss - (Yiddish) craziness; senseless behavior or activity
   • buffoonery, clowning, frivolity, harlequinade, japery, prank - acting like a clown or buffoon
   same as: craziness, folly, foolery, indulgence, tomfoolery

Other Searches

• Rhyme: Dillfrog, RhymeZone
• Definition: Wiktionary, Dictionary.com, Wikipedia, Merriam-Webster, WordNet, Power Thesaurus
• Imagery: Google, Flickr, Bing