From Greek 'leitourgia' (public service) — originally civic duties, adopted by Christians for formal religious worship.
A prescribed form of public worship; the rites and ceremonies used in formal religious services, especially the Christian Eucharist.
From Latin 'liturgia,' from Greek 'leitourgia' (λειτουργία), meaning public service or public duty. The Greek word combines 'leitos' (of the people, public), from 'laos' (people), with 'ergon' (work, deed). In classical Athens, a 'leitourgia' was a public service that wealthy citizens were required to finance — such as equipping a warship or sponsoring a dramatic festival. The Septuagint adopted the word for the service of the Temple priests, and Christianity further narrowed
In classical Athens, a 'leitourgia' was not worship but a tax on the wealthy. Rich Athenians were required to fund public services like equipping a trireme warship (trierarchy) or producing a chorus for dramatic festivals (choregia). The transformation from 'funding a warship' to 'celebrating the Eucharist' is one of the most dramatic semantic shifts in religious vocabulary.