Horrendous means shockingly bad or dreadful. When something is horrendous, it's so terrible that it horrifies or appalls you, far worse than simply poor or disappointing.

A horrendous storm might knock down power lines and flood streets. A horrendous mistake in a recipe could ruin an entire dinner. If your soccer team loses 12 to 0, you might describe it as a horrendous defeat. The word suggests something so bad it makes you wince or recoil.

You might describe horrendous traffic, a horrendous smell, or horrendous behavior. Notice that horrendous is stronger than words like “bad” or “unpleasant.” A slightly burnt pizza is bad; a pizza covered in mold would be horrendous. When something truly deserves to be called horrendous, the word delivers exactly the punch you need.