serviceman n.

c. 1100, "celebration of public religious worship according to prescribed forms or methods," from Old French servise "act of homage; servitude; service at table; Mass, church ceremony," from Latin servitium (in Medieval Latin also servicium) "slavery, condition of a slave, servitude," also "slaves collectively" (in Medieval Latin "service"), from servus "slave" (see serve (v.)).

The meaning "act of serving, occupation of an attendant servant" is attested from c. 1200, as is that of "assistance, help; a helpful act." From c. 1300 as "provision of food; sequence of dishes served in a meal;" from late 14c. as "service at table, attendance during a meal." The sense of "the furniture of the table" (tea service, etc.) is from mid-15c.

Meanings "state of being bound to undertake tasks for someone or at someone's direction" and "labor performed or undertaken for another" are mid-13c. The sense of "service or employment in a court or administration" is from c. 1300, as is that of "military service (especially by a knight); employment as a soldier;" hence "the military as an occupation" (1706).

The meaning "the supplying of electricity, water, gas, etc., for domestic use" is by 1879; later extended to broadcasting (1927), etc. The meaning "expert care or assistance given by manufacturers or dealers to the purchasers of their goods" is by 1919. Service industry (as distinct from production) is attested from 1938; service there indicates the section of the economy that supplies consumer needs but makes no tangible goods (a sense attested by 1936). Service-charge is attested by 1929. A service station originally was a gas stop that also repaired cars.

At your service as a phrase of politeness is attested by c. 1600. Service-book, containing forms for public worship, is attested from 1570s. Also in Middle English, service was "the devotion or suit of a lover" (late 14c.), and "sexual intercourse, conjugal relations" (mid-15c.; service of Venus, or flesh's service). 

"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 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]