Is a continent and a country an adjective?

Answer 1

The word continent is both a noun and an adjective.

An adjective for the noun meaning land mass is continental.

The adjective meaning exercising control of emotions, restraint, or control of the bladder is continent (the noun form is continence).

Answer 2

An adjective must describe a noun, which is an object, place, person, thing, etc. Continents and countries are places, so they are nouns. They also don't describe anything.