en·core / ˈänˌkôr/ • n. a repeated or additional performance of an item at the end of a concert, as called for by an audience.• interj. called out by an audience at the end of a concert to request such a performance.• v. [tr.] (often be encored) give or call for a repeated or additional performance of (an item) at the end of a concert.

encore (Fr.). Again. In Eng. has been adopted as the word of demand for the repetition of a perf. (properly, perhaps, of the same piece, but often used of a return to the platform to give additional perf., either of the same or another piece). Also used as verb (to encore).

Although a Fr. word, encore entered the Eng. language as a corruption of It. ancora (with the same meaning), which, from the early 18th cent. onwards, was used by audiences at the It. Opera in London (together with the words altra volta, another time). The Fr. use bis (Lat., twice; verb bisser).

Encore ★★★ 1952

The third W. Somerset Maugham omnibus (following “Quartet” and “Trio”) which includes: “Winter Cruise,” “The Ant and the Grasshopper,” and “Gigolo and Gigolette.” 85m/ B VHS . GB Nigel Patrick, Kay Walsh, Roland Culver, John Laurie, Glynis Johns, Ronald Squire, Noel Purcell, Peter Graves; D: Pat Jackson, Anthony Pelissier, Harold French; W: Eric Ambler.

encore int. and sb. XVIII. — F. encore again, of uncert. orig.
Hence as vb. XVIII. Not so used in F.