policeman (n.)

1530s, "the regulation and control of a community" (similar in sense to policy (n.1)); from Middle French police "organized government, civil administration" (late 15c.), from Latin politia "civil administration," from Greek polis "city" (see polis).

Until mid-19c. used in England for "civil administration;" application to "administration of public order, law-enforcement in a community" (1716) is from French (late 17c.), and originally in English referred to France or other foreign nations.

The sense of "an organized civil force for maintaining order, preventing and detecting crime, etc." is by 1800; the first force so-named in England was the Marine Police, set up 1798 to protect merchandise at the Port of London. Meaning "body of officers entrusted with the duty of enforcing laws, detecting crime, etc." is from 1810.

In its most common acceptation, the police signifies the administration of the municipal laws and regulations of a city or incorporated town or borough by a corps of administrative or executive officers, with the necessary magistrates for the immediate use of force in compelling obedience and punishing violation of the laws, as distinguished from judicial remedies by action, etc. The primary object of the police system is the prevention of crime and the pursuit of offenders; but it is also subservient to other purposes, such as the suppression of mendicancy, the preservation of order, the removal of obstructions and nuisances, and the enforcing of those local and general laws which relate to the public health, order, safety, and comfort. [Century Dictionary, 1895]

In constitutional law, police power is the power of a government to limit civil liberties and exercise restraint and compulsion over private rights, especially to advance or protect the public welfare. Police state "state regulated by means of national police" first recorded 1865, with reference to Austria. Police action in the international sense of "military intervention short of war, ostensibly to correct lawlessness" is from 1933. Police officer is attested from 1794, American English. Police station is from 1817. Police dog is by 1908.

"a featherless plantigrade biped mammal of the genus Homo" [Century Dictionary], Old English man, mann "human being, person (male or female); brave man, hero;" also "servant, vassal, adult male considered as under the control of another person," from Proto-Germanic *mann- (source also of Old Saxon, Swedish, Dutch, Old High German man, Old Frisian mon, German Mann, Old Norse maðr, Danish mand, Gothic manna "man"), from PIE root *man- (1) "man." For the plural, see men.

Sometimes connected to root *men- (1) "to think," which would make the ground sense of man "one who has intelligence," but not all linguists accept this. Liberman, for instance, writes, "Most probably man 'human being' is a secularized divine name" from Mannus [Tacitus, "Germania," chap. 2], "believed to be the progenitor of the human race."

Specific sense of "adult male of the human race" (distinguished from a woman or boy) is by late Old English (c. 1000); Old English used wer and wif to distinguish the sexes, but wer began to disappear late 13c. and was replaced by man. Universal sense of the word remains in mankind and manslaughter. Similarly, Latin had homo "human being" and vir "adult male human being," but they merged in Vulgar Latin, with homo extended to both senses. A like evolution took place in Slavic languages, and in some of them the word has narrowed to mean "husband." PIE had two other "man" roots: *uiHro "freeman" (source of Sanskrit vira-, Lithuanian vyras, Latin vir, Old Irish fer, Gothic wair; see *wi-ro-) and *hner "man," a title more of honor than *uiHro (source of Sanskrit nar-, Armenian ayr, Welsh ner, Greek anēr; see *ner- (2)).

Man also was in Old English as an indefinite pronoun, "one, people, they." It was used generically for "the human race, mankind" by c. 1200. As a word of familiar address, originally often implying impatience, c.1400; hence probably its use as an interjection of surprise or emphasis, since Middle English but especially popular from early 20c.

As "a woman's lover," by mid-14c. As "adult male possessing manly qualities in an eminent degree," from 14c. Man's man, one whose qualities are appreciated by other men, is by 1873. Colloquial use of the Man for "the boss" is by 1918. To be man or mouse "be brave or be timid" is from 1540s. Meaning "piece with which a game (especially chess) is played" is from c. 1400.

Man-about-town "man of the leisure class who frequents clubs, theaters, and other social resorts" is from 1734. Man of the world is from mid-14c. as "secular man, layman;" by early 15c. as "man experienced in the ways of the world, one able to take things in stride." To do something as one man "unanimously" is from late 14c.

So I am as he that seythe, 'Come hyddr John, my man.' [1473]

MANTRAP, a woman's commodity. [Grose, "Dictionary of the Vulgar Tongue," London, 1785]

At the kinges court, my brother, Ech man for himself. [Chaucer, "Knight's Tale," c. 1386]