world vs terra firma

world and terra firma both are nouns.

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

world (noun)	terra firma (noun)
all of the living human inhabitants of the earth	the solid part of the earth's surface
all of your experiences that determine how things appear to you
the concerns of this life as distinguished from heaven and the afterlife
people in general; especially a distinctive group of people with some shared interest
people in general considered as a whole
the 3rd planet from the sun; the planet we live on
everything that exists anywhere
a part of the earth that can be considered separately

world (adjective)	terra firma (adjective)
involving the entire earth; not limited or provincial in scope