madcap

noun

1. A person who acts in a capricious, impulsive, or reckless manner.

   “Near-synonyms: mad lad, madlad”

   “Come-on you mad-cap: Ile to the Ale-houſe vvith you preſently; […]”

   “There vvas then in preſence, a certaine old Knight, called Sir Hugh Linne, a good ſouldier, but a very mad-cap, & one that liued chiefely vpon the liberalitie of noble men; […]”

   “Lord, that ſuch a Mad-Cap as I ſhould ever live to be jealous!”

   “I should like to have seen that noble old madcap Peterborough in his boots (he actually had the audacity to walk about Bath in boots!), with his blue ribbon and stars, and a cabbage under each arm, and a chicken in his hand, which he had been cheapening for his dinner.”

2. (South-Asia)A very foolish or irresponsible person; a fool, an idiot.

   “[R]un around as he commands. He is a madcap and we must learn to live with him. We are in his hands.”

3. (obsolete, rare)An insane person; a lunatic.

   “VVhy vvhat a mad-cap hath heauen lent vs here?”

   “Bel[lamont]. […] [W]hat place is this? / May[bery]. Bedlam iſt not? / Bel. VVhere theſe mad-men are, I neuer vvas amongſt them, as you loue me Gentlemen, lets ſee vvhat Greekes are vvithin. / […] / Bell. Pray beſtovv your name ſir vpon vs. / Full. My name is Full-moone. / Bell. You vvell deſerue this office good maiſter Full-moone: and vvhat mad-caps haue you in your houſe.”

adj

1. Capricious, impulsive, or reckless; also, bizarre, crazy, zany; or foolish, idiotic.

   “a madcap activity    a madcap idea    a madcap plan”

   “The film featured a madcap car chase that went right through a crowded café.”

   “O lepidum caput, O mad cap maſter.”

   “[H]is mad-cap follies, / VVhich ſtill like Hydras heads grovv thicker on him.”

   “[T]hose fairy times when I was a mad-cap boy, crowding every enjoyment into the present moment; […]”