an adverb.
Her eloquence fit beautifully in a sentence. The nightingale sang beautifully.
It means that you have done something, for example, prettily. In this sentence: "The jump was exectuted beautifully."
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "twirl" is a verb.
The part of speech for "explicit" is an adjective.
The part of speech for "indefinite" is an adjective.