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Synonyms

madcap

American  
[mad-kap] / ˈmædˌkæp /

adjective

  1. wildly or heedlessly impulsive; reckless; rash.

    a madcap scheme.

noun

  1. a madcap person.

madcap British  
/ ˈmædˌkæp /

adjective

  1. impulsive, reckless, or lively

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

  1. an impulsive, reckless, or lively person

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of madcap

First recorded in 1580–90; mad + cap 1

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In a staggering contest of 13 tries and 90 points, Gregor Townsend's men were astonishing in every way until a madcap endgame that saw France run in a battery of tries.

From BBC • Mar. 7, 2026

The Warriors had led until the end of the third quarter, before a madcap finish saw 12 lead changes, with regular time ending 101-101.

From Barron's • Mar. 6, 2026

The Americans had always figured that, at some point, they would be confronted with 3-on-3 overtime—a madcap, frenzied version of the sport that makes 5-on-5 action seem like senior beer league.

From The Wall Street Journal • Feb. 19, 2026

Adapted from Donald E. Westlake’s 1997 novel, appropriately titled “The Ax,” Park’s film immediately acknowledges that the madcap journey viewers are about to see is cyclical, not special.

From Salon • Oct. 7, 2025

I think of her madcap, joyful dresses, of her dust-covered bedroom.

From "The Cruel Prince" by Holly Black

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.