homicide UK /ˈhɒm.ɪˌsaɪ̯d/US /ˈhɑ.məˌsaɪ̯d/ noun4 •the act of killing another person, whether it was planned or not •(US) The department within a police force that investigates cases of homicide. •(US) A victim of homicide; a person who has been unlawfully killed by someone else.We don't even know the woman was a homicide. Didn't they say it was possible they both jumped? — 2003 •A person who kills another.Homicides in general and victorious warriors in particular are often obliged to perform a variety of ceremonies for the purpose of ridding them of the dangerous ghosts of their victims. — 1911 formshomicides