neck vs terra firma

neck and terra firma both are nouns.

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

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

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

neck (noun)	terra firma (noun)
an opening in a garment for the neck of the wearer; a part of the garment near the wearer's neck	the solid part of the earth's surface
a narrow part of an artifact that resembles a neck in position or form
the part of an organism (human or animal) that connects the head to the rest of the body
a cut of meat from the neck of an animal
a narrow elongated projecting strip of land

neck (verb)	terra firma (verb)
kiss, embrace, or fondle with sexual passion