Толковый словарь английского языка Oxford English Reference - opus

n. (pl. opuses or opera) 1 Mus. a a separate musical composition or set of compositions of any kind. b (also op.) used before a number given to a composer's work, usu. indicating the order of publication (Beethoven, op. 15). 2 any artistic work (cf. MAGNUM OPUS). Phrases and idioms opus Dei Eccl. 1 liturgical worship regarded as man's primary duty to God. 2 (Opus Dei) a Roman Catholic organization of laymen and priests founded in Spain in 1928 with the aim of re-establishing Christian ideals in society. Etymology: L, = work