opus

noun, plural o·pus·es or especially for 1, 2, o·pe·ra [oh-per-uh, op-er-uh] /ˈoʊ pər ə, ˈɒp ər ə/.

1. a musical composition.
2. one of the compositions of a composer, usually numbered according to the order of publication.
3. a literary work or composition, as a book: Have you read her latest opus? Abbreviation: op.

Latin.

1. the end crowns the work.

noun plural opuses or opera (ˈɒpərə)

1. an artistic composition, esp a musical work
2. (often capital) (usually followed by a number) a musical composition by a particular composer, generally catalogued in order of publicationBeethoven’s opus 61 is his violin concerto

n.“a work, composition,” especially a musical one, 1809, from Latin opus “a work, labor, exertion” (source of Italian opera, French oeuvre, Spanish obra), from PIE root *op- (Germanic *ob-) “to work, produce in abundance,” originally of agriculture later extended to religious acts (cf. Sanskrit apas- “work, religious act;” Avestan hvapah- “good deed;” Old High German uoben “to start work, to practice, to honor;” German üben “to exercise, practice;” Dutch oefenen, Old Norse æfa, Danish øve “to exercise, practice;” Old English æfnan “to perform, work, do,” afol “power”). The plural, seldom used as such, is opera.