[1] : The Collaborative International Dictionary of English v.0.48

opera \op"era\ o^p"~er.a, n. it., fr. opera work,
   composition, opposed to an improvisation, fr. l. opera pains,
   work, fr. opus, operis, work, labor: cf. f. op'era. see
   operate.
   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.
      1913 webster

   2. the score of a musical drama, either written or in print;
      a play set to music.
      1913 webster

   3. the house where operas are exhibited.
      1913 webster

   opera bouffe f. op'era opera + bouffe comic, it. buffo,
   opera buffa it., 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 f., comic or humorous opera.

   opera flannel, a light flannel, highly finished. --knight.
      

   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 it., serious or tragic opera; grand opera.
      1913 webster
see also:
operate opera bouffe opera buffa opera box opera comique opera flannel 
opera girl opera girls mantisia saltatoria dancing girls opera glass 
opera hat opera house opera seria 

Opera Seria >> O Words
Opera Seria, definition of term: Opera Seria
opera+seria_pag1.html

Opera >> O Words
Opera, definition of term: Opera
opera_pag1.html

Opera House >> O Words
Opera House, definition of term: Opera House
opera+house_pag1.html

Opera Comique >> O Words
Opera Comique, definition of term: Opera Comique
opera+comique_pag1.html

Opera Buffa >> O Words
Opera Buffa, definition of term: Opera Buffa
opera+buffa_pag1.html

Grand Opera >> G Words
Grand Opera, definition of term: Grand Opera
grand+opera_pag1.html

Auxiliary Opera >> A Words
Auxiliary Opera, definition of term: Auxiliary Opera
auxiliary+opera_pag1.html

Light Opera >> L Words
Light Opera, definition of term: Light Opera
light+opera_pag1.html