madcap

American  

[mad-kap] / ˈmædˌkæp /

adjective

1. wildly or heedlessly impulsive; reckless; rash.

   a madcap scheme.

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noun

1. a madcap person.

madcap British  

/ ˈmædˌkæp /

adjective

1. impulsive, reckless, or lively

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noun

1. an impulsive, reckless, or lively person

Etymology

Origin of madcap

First recorded in 1580–90; mad + cap ¹

Explanation

Madcap things are done in a foolish, rash, or impulsive way, without planning or thought. Your madcap adventure might include a spur-of-the-moment bus ride to a nearby city without enough money in your pocket to buy lunch. The adjective madcap, which can simply mean "impetuous," can also have a sense of "funny and eccentric." A movie that's described as a madcap comedy will probably be full of broad slapstick and laugh-out-loud physical humor. Madcap, dating from the 16th century, originally meant "lunatic" or "crazy person," from the "head" sense of cap — in other words, a madcap was a "crazy head."

Example Sentences

In “Exit the King,” he confronts the insupportable reality of death with the same madcap delirium of his better known works, such as “The Bald Soprano,” “The Chairs” and “Rhinoceros.”

From Los Angeles Times • May 13, 2026

Ms. Lemann was a friend and acolyte of Percy, but where “The Moviegoer” is brooding, “Lives of the Saints” is madcap.

From The Wall Street Journal • Apr. 23, 2026

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

Letters proposing madcap, unpublished ideas, often accompanied by hand-scribbled figures, were circulated among the members; it was a blog before blogs.

From "The Gene" by Siddhartha Mukherjee