The word adverb is a noun. However, adverbs (the words that modify verbs, adjectives, and other adverbs) are their own part of speech.
adverb
Adverb
Adverb
adverb
"Ever" is an adverb.
Twice is an adverb.
Commonly is an adverb.
Hysterically is an adverb.
Beautifully is an adverb.
adverb
Recently is an adverb.
Beautifully is an adverb.