From Longman Dictionary of Contemporary Englishmadcapmad‧cap /ˈmædkæp/ adjective [only before noun] old-fashioned 1 STUPID/NOT SENSIBLEa madcap idea seems crazy and unlikely to succeed a madcap scheme2 a madcap person behaves in a crazy and often funny way He plays a madcap game show host.
Examples from the Corpus
madcap• a madcap adventure• Behind the madcap narrative is a deeper purpose.