Foolhardy means recklessly bold or taking dangerous risks without thinking them through. A foolhardy person rushes into danger without considering the consequences, mistaking carelessness for courage.

If your friend dares you to climb onto your roof during an ice storm, that's a foolhardy idea: it might seem brave, but it's actually just dangerous and thoughtless. A foolhardy explorer might venture into a blizzard without proper supplies, or a foolhardy knight might charge alone against an entire army.

A firefighter rushing into a burning building to save someone is brave because they're trained, equipped, and acting with purpose. But someone running into that same building on a whim, without training or equipment, would be foolhardy. When you face a genuine challenge, like trying out for the school play even though you're nervous, that takes real courage. But jumping your bike off a homemade ramp without a helmet or practice is foolhardy, ignoring risks rather than understanding them.