slang Someone who is too nervous, afraid, or reserved to do anything too intense, extreme, or risky. We're all doing the bungie jump. Don't be a wuss, Bob! I remember calling other kids wusses because they didn't want to smoke, but now I realize that they were the brave ones.

slang To withdraw from doing something out of fear, insecurity, or laziness. They were just about to strap me in for the bungie jump, but I wussed out at the last second. Jeff had promised to help, but he wussed out of the project when he realized how much work it would entail. Sorry, guys, Janet's wussing out of the road trip. She says she isn't comfortable being away from home for that long.