Perilous means extremely dangerous, full of serious risk or threat. When mountain climbers face a perilous descent down an icy slope, one wrong step could lead to disaster. When sailors navigate perilous waters filled with hidden rocks and sudden storms, they know their lives depend on skill and caution.

The word suggests more than ordinary danger. A math test might be difficult, but it's not perilous. A perilous situation threatens real harm: injury, loss, or even death. Explorers crossing Antarctica faced perilous conditions where mistakes could be fatal. A tightrope walker performs a perilous feat high above the ground.

You'll often encounter perilous in adventure stories where characters brave dangerous journeys or face life-threatening challenges. When something is perilous, it demands respect, preparation, and courage. Recognizing when a situation is truly perilous, rather than just uncomfortable or scary, can make the difference between taking smart risks and foolish ones.