Opera n. 1.A drama, either tragic or comic, of which music forms an essential part; a drama wholly or mostly sung, consisting of recitative, arias, choruses, duets, trios, etc., with orchestral accompaniment, preludes, and interludes, together with appropriate costumes, scenery, and action; a lyric drama.
2.The score of a musical drama, either written or in print; a play set to music.
3.The house where operas are exhibited.
Opera bouffe, Opera buffa, light, farcical, burlesque opera.
Opera box, a partially inclosed portion of the auditorium of an opera house for the use of a small private party.
Opera comique, comic or humorous opera.
Opera flannel, a light flannel, highly finished.
Opera girl or Opera girls (Bot.), an East Indian plant (Mantisia saltatoria) of the Ginger family, sometimes seen in hothouses. It has curious flowers which have some resemblance to a ballet dancer, whence the popular name. Called also dancing girls.
Opera glass, a short telescope with concave eye lenses of low power, usually made double, that is, with a tube and set of glasses for each eye; a lorgnette; so called because adapted for use at the opera, theater, etc.
Opera hat, a gentleman's folding hat.
Opera house, specifically, a theater devoted to the performance of operas.
Opera seria, serious or tragic opera; grand opera.
...