The Collaborative International Dictionary of English v.0.48:

Musical \Mu"sic*al\, a. [Cf. F. musical.]
   Of or pertaining to music; having the qualities of music; or
   the power of producing music; devoted to music; melodious;
   harmonious; as, musical proportion; a musical voice; musical
   instruments; a musical sentence; musical persons.
   [1913 Webster]

   Musical box, or Music box, a box or case containing
      apparatus moved by clockwork so as to play certain tunes
      automatically. The apparatus may be driven by a wind-up
      spring mechanism or by batteries.

   Musical fish (Zool.), any fish which utters sounds under
      water, as the drumfish, grunt, gizzard shad, etc.

   Musical glasses, glass goblets or bowls so tuned and
      arranged that when struck, or rubbed, they produce musical
      notes. Cf. Harmonica, 1.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Musical \Mu"sic*al\, n.
   1. Music. [Obs.]
      [1913 Webster]

            To fetch home May with their musical. --Spenser.
      [1913 Webster]

   2. A social entertainment of which music is the leading
      feature; a musical party. [Colloq.]
      [1913 Webster]

   3. A drama in which music and song are prominent features; a
      musical drama or musical play; as, Oklahoma! was a
      breakthrough in the form and popularity of the musical.
      [PJC]

WordNet (r) 3.0 (2006):

musical
    adj 1: characterized by or capable of producing music; "a
           musical evening"; "musical instruments"
    2: talented in or devoted to music; "comes from a very musical
       family" [ant: nonmusical, unmusical]
    3: characteristic of or resembling or accompanied by music; "a
       musical speaking voice"; "a musical comedy" [ant:
       nonmusical, unmusical]
    4: containing or constituting or characterized by pleasing
       melody; "the melodious song of a meadowlark" [syn:
       melodious, melodic, musical] [ant: unmelodic,
       unmelodious, unmusical]
    n 1: a play or film whose action and dialogue is interspersed
         with singing and dancing [syn: musical, musical comedy,
         musical theater]

Moby Thesaurus II by Grady Ward, 1.0:

126 Moby Thesaurus words for "musical":
   Broadway musical, Singspiel, Thalia, achingly sweet, agreeable,
   agreeable-sounding, appealing, ariose, arioso, arlequinade,
   ballad opera, ballet, ballet divertissement, black comedy,
   blending, broad comedy, burlesque, burletta, camp, canorous,
   cantabile, catchy, chiming, chorus show, comedie bouffe,
   comedie larmoyante, comedie rosse, comedietta, comedy,
   comedy ballet, comedy of humors, comedy of ideas,
   comedy of intrigue, comedy of manners, comedy of situation,
   comedy relief, comic muse, comic opera, comic relief, consonant,
   dance drama, dark comedy, domestic comedy, dulcet, euphonic,
   euphonious, euphonous, exode, farce, farce comedy, fine-toned,
   genteel comedy, golden, golden-tongued, golden-voiced, grand opera,
   harlequinade, harmonic, harmonious, high camp, honeyed,
   light comedy, light opera, low camp, low comedy, lyric drama,
   lyrical, melic, mellifluent, mellifluous, mellisonant, mellow,
   melodic, melodious, mime, minstrel, minstrel show, music drama,
   music-flowing, music-like, music-loving, musical comedy,
   musical stage, musical theater, musically inclined, musicianly,
   musicophile, opera, opera ballet, opera bouffe, opera buffa,
   operetta, philharmonic, pleasant, pleasant-sounding, raw comedy,
   realistic comedy, rich, romantic comedy, satyr play,
   sentimental comedy, silver-toned, silver-tongued, silver-voiced,
   silvery, singable, situation comedy, slapstick, slapstick comedy,
   song-and-dance act, song-play, songful, songlike, sonorous, sweet,
   sweet-flowing, sweet-sounding, symphonic, symphonious, tragicomedy,
   tunable, tuned, tuneful, virtuose, virtuosic, virtuoso