Behaving or acting impulsively or rashly; wild.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "madcap" in a sentence
"Aug. 3 Bloomberg -- Governor Zhou Xiaochuan said China's central bank will monitor U.S. efforts to tackle its debt as the official Chinese news agency criticized what it called the "madcap" brinksmanship of American lawmakers."
"How much more so must it be to papa, though he likes you, and when you are near him would perhaps, in a fit of unworldliness, be almost as reckless as the creature he calls madcap and would rather call countess."
"It referred to a "madcap farce of brinksmanship" before the agreement was reached."