service (n.1)
c.1100, "celebration of public worship," from Old French servise "act of homage; servitude; service at table; Mass, church ceremony," from Latin servitium "slavery, condition of a slave, servitude," also "slaves collectively," from servus "slave" (see serve (v.)).

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." Meaning "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; labor performed or undertaken for another" are mid-13c. 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).

Also in Middle English "sexual intercourse, conjugal relations" (mid-15c.; service of Venus, or flesh's service). Service industry (as distinct from production) attested from 1938. A service station originally was a gas stop that also repaired cars.
service (v.)
1893, "to provide with service," from service (n.1). Meaning "perform work on" first recorded 1926. Related: Serviced; servicing.
service (n.2)
type of tree or berry, extended form of serve (perhaps via Middle English plural serves being taken as a singular), from Old English syrfe, Old French sorbe, both from Vulgar Latin *sorbea, from Latin sorbus (see sorb).