A verb.
Fearfully is an adverb. It is describing how something is done in a fearful manner.
'Fear' can be a noun; i.e 'to have a fear of something', or it can be a verb; i.e 'to fear something'.
He was referring to the depression and the us economy.
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.