匹夫之勇

pǐfūzhīyǒng

foolhardiness; courage without wisdom or prudence

Wiktionary

Entry Composition

1 匹夫 pǐfū
  1. ordinary man
  2. ignorant person
  3. coarse fellow
2 之 zhī
  1. (possessive particle, literary equivalent of 的 de)
  2. him
  3. her
  4. it
3 勇 yǒng brave