calliope vs steam organ

calliope and steam organ both are nouns.

Word	Noun	Adjective	Verb	Adverb
calliope	Yes	No	No	No
steam organ	Yes	No	No	No

As nouns, calliope and steam organ are synonyms defined as:

calliope and steam organ: a musical instrument consisting of a series of steam whistles played from a keyboard

calliope (noun)	steam organ (noun)
a musical instrument consisting of a series of steam whistles played from a keyboard	a musical instrument consisting of a series of steam whistles played from a keyboard