It's an adverb.
He stared at the boy dreadfully with anger. This is a sentence using the word dreadfully.
The party was dreadfully boring. She dreadfully approached the door, expecting death at any moment.
He fell asleep during the lecture because it was dreadfully boring. I need to hire more help because we are dreadfully short handed. He couldn't find the assignment and his locker is dreadfully unorganized.
The root base of "dreadfully" is "dread", which means to anticipate with fear or apprehension. The suffix "-fully" is added to form the adverb "dreadfully", meaning in a manner causing great fear or apprehension.
weaponry & federally... (?)
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
3. Idiot.
The part of speech for "unfamiliar" is an adjective.