! Policeis a plural noun. Do not say 'a police'. Say apolice officer,apoliceman,or a policewoman:The police were called.|A police officer came. ➔military police, secret policeWORD FOCUS: police WORD FOCUS: police people in the police force:police officer, policeman, policewoman, detective, copinformal the building where the police work:police station what the police do:investigatecrimes, find/collectevidence, arrest people who they think are guilty of a crime,question/interrogate people about crimes,hold/detain people in custody, charge people with crimes,release people if they are innocent
Definition from the Longman Dictionary of Contemporary English Advanced Learner's Dictionary.