In 2009, J C McKeown of the University of Wisconsin described his book Cabinet of Roman Curiosities as an opusculum, an assessment both appropriate and modest. An opusculum is a little work, usually a book.
For most of us, opusculum means nothing, which disgusted the late Anthony Burgess. In one of his diatribes in old age lamenting the decline of education he challenged guests at his dinner table with idiolect, palinlogue, desquamation, lesbic, autophagous, monophthongal, autocephalous, inesculent, allomorph, strabismus ... and opusculum.
I may return to some of these another time, but for the moment must restrict myself to explaining that opusculum is the diminutive of Latin opus. For the Romans, opus was any sort of labour, but it has come to mean an artistic work, in particular one on a large scale. We meet it most frequently in music but it can be used of books, paintings and other media. It appears also in magnum opus, literally “great work”, the most important creation of an artist. Burgess would undoubtedly have known that if one were in the unlikely situation of wanting to discuss the most significant output of several artists, one should describe them as their magna opera.
Though opera is the plural of opus it’s rarely used that way, since opera has taken on a life of its own as a singular noun for the musical genre. This came about in Italian, in which it meant a composition in which poetry, dance, and music were combined, thus including several types of opus.
The plural of opusculum is opuscula, which widely appears in scholarly contexts but is otherwise rare.
It is many years since Sir Sacheverell Sitwell’s Collected Poems appeared: more than 40, indeed. Since then, a few privately printed opuscula have been distributed among friends.
Financial Times, 7 Aug. 1982.