"坏蛋" (huàidàn) is a Chinese word that means "villain" or "bad person." In Engpsh, we might say "bad guy" or "villain" to refer to someone who is dishonest or mapcious. For example, you might say "He's the bad guy in the movie" or "She's the villain of the story." Other words that might be used to describe a bad person in Engpsh include "crook," "scoundrel," "fiend," "rogue," "rascal," or "nogoodnik."