It is neither an adjective nor an adverb. "Plethora" is a noun.
Use it like you might use the nouns "abundance" "quantity" or "excess", when what you want to convey is "huge amount" or "overabundance".
I don't think it is often pluralized; have never seen that, anyway.
Also rare would be its adjective form "plethoric", leading to a stretch to make the adverb "plethorically".
Good for "plethora" for being one of those words that has very very few relatives in the language!
An adverb describes a verb, an adjective or another adverb.
The word small can be an adjective or an adverb.
Approximate is an adjective, approximately is an adverb.
Persistence is not an adjective or an adverb. It's a noun.
The word very is an adverb.
Dark can be an adjective or a noun. Darkly is an adverb.
Night: noun an: adverb adjective: adjective noun: noun adverb: adverb
Adverb.Here is an adverb, not an adjective.
An adverb describes a verb, an adjective or another adverb.
its an adverb an adjective is a descriptive word an adverb is a feeling
The adjective of strength is strong.The adverb of strength is strongly.
It can be an adjective OR an adverb. adjective -- You dog is a friendly dog adverb -- She always talks friendly to me
Nervous is an adjective. The adverb form is nervously.
No, it is an adverb. It is the adverb form of the adjective perfect.
'The' is neither an adjective nor an adverb. It is an article.
The word small can be an adjective or an adverb.
No, it is an adverb. It is the adverb form of the adjective contented.