Do in Definition 1 of 3Pro Tip 1/3Violent Connotation Used to imply a brutal or aggressive action, suggesting an illegal or immoral killing. In the movie, the spy was done in without mercy. Pro Tip 2/3Mystery and Crime Commonly appears in crime fiction or discussions about mysterious deaths. Detectives believed the butler had done the heir in. Pro Tip 3/3Not Literal Sometimes used humorously or dramatically to describe a less serious defeat or failure. My last exam really did me in.