From Middle English folehardy, foolhardi, folherdi, from Old French fol hardi, from Old French fol (from Latin follis, ultimately from Proto-Indo-European *bʰelǵʰ-) + Old French hardi (past tense of hardir ("to harden"), from the unattested Frankish *hartjan, from Proto-Germanic *harduz), equivalent to fool + hardy.

• (RP) IPA: /ˈfuːlhɑːdi/
• (America) IPA: /ˈfulˌhɑɹdi/

foolhardy (comparative foolhardier, superlative foolhardiest)

1. Marked by unthinking recklessness with disregard for danger; boldly rash; hotheaded.
   • 1876, Mark Twain [pseudonym; Samuel Langhorne Clemens], chapter VI, in The Adventures of Tom Sawyer, Hartford, Conn.: The American Publishing Company, →OCLC ↗, page 68 ↗:

     The master's pulse stood still, and he stared helplessly. The buzz of study ceased. The pupils wondered if this fool-hardy boy had lost his mind.

• bold
• daring
• foolish
• irresponsible
• rash
• reckless

• French: tête brûlée
• German: töricht, tollkühn, vermessen, verwegen, ungestüm, hitzköpfig, dummdreist, waghalsig
• Italian: avventato, spericolato, imprudente, dissennato
• Russian: безрассудно храбрый
• Spanish: temerario

foolhardy (plural foolhardies)

1. A person who is foolhardy.
   • 1977, Rolf R. Mueller, Festival and Fiction in Heinrich Wittenwiler's Ring, page 26:

     Resentful of the saddle-fast stranger, eight foolhardies return for more adventure.

   • 2019, Colson Whitehead, The Nickel Boys:

     Some foolhardies in the schoolhouse laughed at him then and Griff stuck their heads into toilets, one by one over the next week.