don't waste time시간 낭비하다 means “to waste time.” 시간 낭비하지 is commonly followed by 마, 마라, 말고, or 말자 to form expressions such as “don’t waste time,” “instead of wasting time,” or “let’s not waste time.”
KO: 시간 낭비하지 말고 바로 시작하자.
EN: Let’s not waste time and get started right away.