Officer and police officer are still and increasingly the best Standard designations for a member of a police force; sometimes police officers are distinguished from other officers by being called peace officers, especially if they’re not actually police but rather are sheriffs, deputies, marshals, constables, etc. Although technically a patrolman is not an officer, the term is the only word that will work in direct address except another rank: What’s the problem, officer [sergeant]? Unlike policeman and policewoman, police officer and officer are inclusive. Cop is still widely used and is also inclusive, but it’s slang.
