Blackmail/ˈblækmeɪl/ Definition 1 of 2Pro Tip 1/3Implied Power Blackmail suggests one person has power over another by holding a damaging secret. With the blackmail, he controlled her every decision. Pro Tip 2/3Negative Connotation Blackmail is illegal and unethical, carrying a strong negative moral judgment. Blackmail is a crime, and culprits are viewed with disdain. Pro Tip 3/3Cultural References In movies, blackmail is a common plot device, often resulting in suspense. The thriller centered on a devastating act of blackmail.