"Ancient" can either be an adjective or a noun, depending on the context of usage.
Examples:
"Ancient" as an adjective:
The Great Pyramids, the Sphynx, and hieroglyphs are all elements of Ancient Egypt.
"Ancient" as a noun:
Ancients in the tribe are respected for their wisdom and experience.
adverb
what part of speech is beneath
i want to know what part of speech is camping
The part of speech is a adjective
Oppose is a verb.
Adjective.
The word antediluvian is an adjective. It describes something which is ancient.
The word "agora" is a noun. It refers to ancient Greek marketplaces or public squares.
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
"Frightening" is an adjective, as it describes a noun, e.g. The ancient, gnarled tree made a frightening shape in the moonlight.
The part of speech for "explicit" is an adjective.
The part of speech for "twirl" is a verb.
The part of speech for "unfamiliar" is an adjective.