A "draw no bet" or "tie no bet" in soccer betting is just what it sounds like you're betting a team to win, and if it ends in a draw, your bet will be refunded. This is a popular way to back a team with a bit of a safety net, albeit at a worse price than you'd get on the regular three-way line that includes a draw.
One of the most popular betting markets for mitigating risk is the draw no bet. It's a market that can be accessed across multiple sports, and used frequently by shrewd bettors to remove the draw outcome from markets, such as the moneyline.