- Also called steam organ. a musical instrument consisting of a set of harsh-sounding steam whistles that are activated by a keyboard.
- (initial capital letter) Also Kalliope. Classical Mythology. the Muse of heroic poetry.
- US and Canadian a steam organ
- Greek myth the Muse of epic poetry
1858, “steam-whistle keyboard organ,” named for Calliope, ninth and chief muse, presiding over eloquence and epic poetry, Latinized from Greek Kalliope, literally “beautiful-voiced,” from kalli-, combining form of kallos “beauty” + opos (genitive of *ops) “voice,” related to Latin vox (see voice (n.)).