wonderland vs terra firma

wonderland and terra firma both are nouns.

Word	Noun	Adjective	Verb	Adverb
wonderland	Yes	No	No	No
terra firma	Yes	No	No	No

As nouns, terra firma is a hypernym of wonderland; that is, terra firma is a word with a broader meaning than wonderland:

Other hypernyms of wonderland include dry land, earth, ground, land, solid ground.

wonderland (noun)	terra firma (noun)
an imaginary realm of marvels or wonders	the solid part of the earth's surface
a place or scene of great or strange beauty or wonder