1550s, Liturgy, "the service of the Holy Eucharist," from French liturgie (16c.) or directly from Late Latin/Medieval Latin liturgia "public service, public worship," from Greek leitourgia "a liturgy; public duty, ministration, ministry," from leitourgos "one who performs a public ceremony or service, public servant," from leito- "public" (from laos "people;" compare leiton "public hall," leite "priestess;" see lay (adj.)) + -ourgos "that works," from ergon "work" (from PIE root *werg- "to do"). Meaning "collective formulas for the conduct of divine service in Christian churches" is from 1590s. Related: Liturgist; liturgics.
In ancient Greece, particularly at Athens, a form of personal service to the state which citizens possessing property to a certain amount were bound, when called upon, to perform at their own cost. These liturgies were ordinary, including the presentation of dramatic performances, musical and poetic contests, etc., the celebration of some festivals, and other public functions entailing expense upon the incumbent; or extraordinary, as the fitting out of a trireme In case of war. [Century Dictionary]