How do you describe a police officer on duty, who wears casual clothes because he/she doesn't want to disclose his/her identity?

  • 5
    You may want undercover, incognito or disguised. Please add context. Oct 29, 2013 at 23:40
  • 3
    Chris Chen, saying "at his duty" is extremely unusual and awkward. It is much more common to say on duty. There is an example of it being used, at this link dictionary.cambridge.org/dictionary/british/duty_1?q=duty
    – Tristan
    Oct 30, 2013 at 0:12
  • Tristan is correct. I left it alone while editing simply because I didn't want to change even more than I did.
    – MrHen
    Oct 30, 2013 at 0:35
  • Chris Chen, that's good and easier to read, now. It would probably be more accurate to adjust the term policeman to police officer because, many parts of the world also have police women.
    – Tristan
    Oct 30, 2013 at 19:39

4 Answers 4


If the policeman is wearing everyday clothes as part of an assignment, if he or she is on duty at the moment and normally wears a uniform but not for this particular job, then I would say undercover. Undercover implies that the policeman is actively trying to hide the fact that they are police.

Plainclothes is usually used to describe officers who don't wear uniforms in general. For example, detectives tend to not wear uniforms, or so I gather from TV police shows. I admit I don't have much experience in this field.

If the policeman is simply at home and dressed normally, I would just say that they are not in uniform.

Finally, some other terms you might consider are (definitions from the Free Dictionary):

Civilian dress, especially when worn by one who normally wears a uniform.

Civilian clothes.

  • 9
    Using the word mufti in this context, is unusual. Using civvies or civilian clothes is more common.
    – Tristan
    Oct 30, 2013 at 0:21
  • 2
    I never even knew about this meaning of ‘mufti’—never heard that used. I only know it as an Arabic title … and as a mildly derogatory term for people of Arabic descent in general. Oct 30, 2013 at 0:53
  • 1
    @JanusBahsJacquet believe it or not, I picked that up when reading Asterix in Britain (translated into English) as a young child in the 80s. The translation was probably from the 70ies or earlier, I don't remember. The word was unknown to me but it has stuck. I can't find a reference showing the actual panel (though I remember it clearly) but you can see it mentioned in the annotations here, page 32, panel 8.
    – terdon
    Oct 30, 2013 at 1:04
  • 2
    @JanusBahsJacquet: interesting — I (growing up in the UK in the 80’s/90’s) only knew it in the “non-uniform clothes” sense described above. Where does it get used pejoratively?
    – PLL
    Oct 30, 2013 at 3:16
  • 3
    'Mufti' is one of the words that has entered English via British India of which there are scores in everyday use. A lot, in my experience, are unknown to Americans. Words like 'bungalow' ,meaning a single-story house, 'gymkhana' a small horse riding competition, usually for children, etc. Even the nickname for Britain, which every British soldier and ex-pat uses at some stage, 'Blighty' (re song 'Take me back to dear old Blighty') comes from the Hindi word meaning 'foreign parts'. Colloquialisms like 'let's have a "dekko" at your new car', meaning 'a look', is another from the sub-continent.
    – WS2
    Oct 30, 2013 at 19:47

In America and the UK the officer would be called plainclothes.

From the Free Online Dictionary:

plainclothes - Wearing civilian clothes while on duty to avoid being identified as police or security

  • 3
    Lumberjack, people also say plain clothes, in the UK.
    – Tristan
    Oct 30, 2013 at 0:02
  • 3
    I'd use plainclothesman (the noun form).
    – lily
    Oct 30, 2013 at 2:21
  • @Lumberjack: Even in India, I've come across them being described as "Plainclothesmen"
    – kumarharsh
    Oct 30, 2013 at 7:16

Undercover agent

Being undercover is disguising one's own identity or using an assumed identity for the purposes of gaining the trust of an individual or organization to learn secret information or to gain the trust of targeted individuals in order to gain information or evidence. Traditionally it is a technique employed by law enforcement agencies around the world and a person who works in such a role is commonly referred to as an undercover agent.

The agent is still a police officer working on duty and may very well dress in civilian clothes in order to disguise his real identity.

M.W has this to say for undercover: done or working in a secret way in order to catch criminals or collect information; "for months she's been an undercover agent pretending to be a drug dealer"

  • 'Undercover agent' sounds a bit sinister to me. UK police forces are organised in two sections 'uniform branch', and 'plainclothes branch'. The ranking system is slightly different. the plainclothes officers have the letter D in front of their rank. Thus the lowest rank of uniformed officer is a PC (Police Constable). His plainclothes equivalent is a DC (Detective Constable). These appendages go all the way up the system through Sergeant, Inspector, Superintendent, and Chief Superintendent. When you get to Assistant Chief Constable the ranking system merges. (cont'd)
    – WS2
    Oct 29, 2013 at 23:50
  • Uniformed officers do on occasions wear plain clothes. If they need to go to visit a witness, for example, and the witness is sensitive about his neighbours seeing a uniformed police officer appearing at his house, then the policeman may agree to go in plain clothes. What type of clothes the plainclothes officers wear will very much depend on the type of work they are doing.
    – WS2
    Oct 29, 2013 at 23:54
  • @WS2 This is an American term, and the first word I thought of when I read the OP's question. Yes, a plain clothes officer is a police officer who wears civilian clothes but the OP said:*"if he doesn't want to disclose his identity"*. Undercover fits the bill.
    – Mari-Lou A
    Oct 29, 2013 at 23:55
  • WS2, what you described as the 'plainclothes branch', is called CID, in the UK, dictionary.cambridge.org/dictionary/british/cid?q=CID
    – Tristan
    Oct 29, 2013 at 23:58
  • @Tristan Yes I have just looked it up and you are right. For some strange reason I thought the name Criminal Investigation Department (CID) had been abolished. The expression seems seldom used nowadays, in the way it once was.
    – WS2
    Oct 30, 2013 at 0:04

In the United States, the most commonly-known form of undercover policing is the Drug Enforcement Agency's implementation of narcotics officers in areas with rapidly-growing illicit drug distribution. While some of these are cooperative citizens after being convicted of a posession-related misdemeanor, many are active police officers. In either case they are commonly referred to by both sides of the "War on Drugs" as narcs, short for narcotics informant. And also, both the DEA and the users/distributors of illegal drugs use snitch and rat as slightly more derogatory synonyms to narc. The justification for referring to these individuals with degradation centers around the narc's use of deceit and strategic exploitation of trust in the clear interest of either self-advancement or self-preservation.

The noun spy is worth mentioning. One can assume that an on-duty police officer, intentionally hiding his involvement in law enforcement, is engaged in some form of social manipulation with the purpose of obtaining private information. Perhaps the archetypal spy caricature perpetuated by numerous media franchises prevents us from using such an accessible and suitably-defined word as spy in a serious manner, but it takes very little time for the novelty of a word's invocation of ideative silliness to be outweighed by the word's simple practicality.

If none of these available nouns suffice, I have a more abstract suggestion. The noun badge could be used to describe an on-duty police officer intentionally not dressed in uniform. One can imagine the actual policeman's badge - hidden snugly away in a wallet in a pocket - as symbolic of the man's identity as a cop. It is also not derogatory, communicates the idea of a personified mark of honor, as in a badge of courage, and has the feature of communicating a shell of an identity, e.g. "Anyone can see the man is a badge yet you continue associate to with him, blinded by your emotions!"

Not the answer you're looking for? Browse other questions tagged or ask your own question.