Noun, verb or adjective
On the mountain top is a preposition phrase, not a part of speech.
noun the meaning is the top of a mountain or hill
She appareled all the top musicians. - past tense.
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
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.
The part of speech of "came" is a verb.