fantasia

[fan-tey-zhuh, -zhee-uh, fan-tuh-zee-uh] /fænˈteɪ ʒə, -ʒi ə, ˌfæn təˈzi ə/
noun
1.
Music.
  1. a composition in fanciful or irregular form or style.
  2. a potpourri of well-known airs arranged with interludes and florid embellishments.
2.
fantasy (def 9).
3.
something considered to be unreal, weird, exotic, or grotesque.
Origin
1715-25; < Italian; see fantasy
British Dictionary definitions for fantasia

fantasia

/fænˈteɪzɪə; ˌfæntəˈzɪə/
noun
1.
any musical composition of a free or improvisatory nature
2.
a potpourri of popular tunes woven freely into a loosely bound composition
3.
another word for fancy (sense 13)
Word Origin
C18: from Italian: fancy; see fantasy
Word Origin and History for fantasia
n.

"musical composition that sounds extemporaneous," 1724, from Italian fantasia, from Latin phantasia (see fantasy).